Are your touring-riding clothes a lot different than, let say, clothes for riding to work? Do you wear better or different clothes for touring? Have you found some good way to wash your clothes during touring? And how does washing affect your choice of clothing? How do you keep your touring clothes during touring? You surely need to separate dirty, clean and wet-clean clothes. How do you manage them? If you just washed your clothes in some sea and you need to continue riding, how do you guarantee that the water will evaporate? Do you choose your clothes in a way that they get dry fast? Which criteria you have for touring clothes?
You need clothes that dry quickly - stuff you can put on wet and will dry in minutes.
For washing - this stuff (called "Campsuds") does laundry, hair, body, bikes everything, biodegradable non-toxic etc.
When packing for a tour, I'll often spend as much time deciding which clothing to pack as I will for all other packing combined. What clothing one wears on tour is a personal decision, based on the rider's preferences. Below, I've written what I wear, and why I prefer it.
When riding, I wear padded lycra cycling shorts with breathable t-shirts. I'll usually bring two or three pairs of shorts, two t-shirts, and three pairs of wool cycling socks. I'll also bring along a pair of tights to wear over the shorts in the morning, and a light cycling jacket. Even in the hottest part of the summer, it's quite cold in the morning where I live, so this is important. Lycra dries fast, and that's part of why I wear it, but my primary reason is that it's comfortable.
Cleaning clothing: Lycra washes easily and dries fairly quickly. I'll usually stop at a laundromat to do a load of laundry a few days into the tour; sometimes my host for the night may offer the use of a laundry machine and dryer. If I know I won't get a chance to do this, I'll wash my shorts and socks by hand in a public restroom. (Some cycling shorts specify washing by hand or on a gentle cycle anyway.) I don't worry about wearing a dirty shirt or tights, but I don't want to re-wear sweaty shorts or socks.
If you camp in areas that don't have public restrooms, you'll want to get camping soap that won't harm the environment, like mgb wrote.
Drying: I'll bring a clothesline along with me and string it between two trees, but when it's humid out, that won't always work. In that case, I'll hand my clothing to the outside of the camping roll that's strapped to my rear rack, tucking the clothing under the bungee cords. An hour or two in the wind will dry just any cycling clothing. If I have a trailer with me, so much the better; there's more space to act as a drying rack.
In cold weather or rain, I'll have more clothing. Some of these can be washed the same way as lycra, such as the balaclava and glove liners, but some cannot: rain pants, a rain jacket, heavier cycling pants, winter gloves, and so on. Any of these heavier items that need to be washed can wait until I get to a laundry machine. (You don't sweat much in the winter in any case.)
I'll also pack off-bike clothing. I tend to favor cotton pants or shorts, black tee-shirts, and sweat socks. These roll up tightly, and are comfortable. I'll also bring something to sleep with, although clean bicycle tights and cycling jackets are good extra layers for cold nights in a tent. Cleaning cotton, which is unsuitable for riding in any case, will wait until I get to a laundromat.
In my panniers, I'll segregate dirty clothing from clean by bringing along a few plastic grocery bags and sealing the dirty clothes in them as best as I can. While doing laundry, I'll sometimes let my panniers air out.
In summary, a little time spent planning will help keep your panniers light, and an hour or two spend every other day will keep your critical clothing clean.
I travel with at least three sets of clothes.
I also carry a full covering of polypropylene and a few extra pairs of socks (which can also be used as mittens). In the snow I carry more over-clothing, but usually I just carry a cycling windbreaker and a polarfleece jumper. On the road I hand-wash every day and dry stuff overnight/in the afternoon after I finish riding. When it rains I get wet, usually stripping down to the windbreaker and polypro.
I carry lightweight off-bike footwear (jandals or crocs) and my only shoes are SPD ones that I wear while riding. I also have a sunhat with neck protection, and often my long-sleeved tops have hoods which work better than a sunhat while riding. I sometimes use pins to attach my sleeves to my gloves to cover the gap at my wrists. Sun in the southern hemisphere is not kind to us light-skinned people.
My goal is riding clothes to suit the conditions, and off-bike clothes more suited to dress-up occasions where I can't really wear my cycling clothes. Everything needs to be fairly long-lasting, easy to dry and ideally not a colour that shows the dirt easily.
My wife and I spent two months of summer 2012 biking around Europe. So this answer is necessarily biased towards temperate-to-warm region where it rains. There are a several places where I've made brand references; I'm not associated with any of these companies, but some items were just so good that they are worth mentioning specifically. This is what I brought:
A. On-bike clothes
One of my main priorities was to be covered from the sun as much as possible, so I would have to wear as little sunscreen as possible -- it gets sticky after a day of riding, and possibly toxic (particularly if you're putting it on every single day all over).
(1) Mid-calf polyester pants ("capris"). I took a pair of Sickle Crux climbing pants and cut them mid-calf to have maximum sun protection. They're made out of really comfortable and slick nylon that lasts a long time.
(2) White long sleeve polyester shirt. I used the Patagonia Forerunner shirt (which sadly no longer comes in white), and it was excellent. I had another similar shirt on this trip but would bring two Forerunners next time since they are lighter weight but still block the sun.
(3) Bandanna. Makes me look like I am German, but it keeps the back of my neck from getting burned.
(4) Socks. I hate wearing dirty socks. While I'm normally a minimalist, I brought about four pairs of socks and didn't regret it. Thin, biking-specific socks -- Pearl Izumi, Sock Guy. Also polyester for quick drying.
(5) Yellow biking jacket. My wife and I both have Pearl Izumi's yellow biking jackets and love them. Well ventilated, well made. I've had mine for seven years now I think.
(6) Really Comfortable Shoes. Again Pearl Izumi here, with their X-Alp shoes, which worked as both on- and off-bike shoes.
(7) Bike gloves. Because you don't want to rip up your hands if you crash. Also for sun protection.
That's it. One item that is missing that most people would have on this list, and before this trip I would have thought would be crazy to omit, is bike shorts. But after a few days in warm weather, on long biking days with breaks in the middle, I found that I valued ventilation over padding (by a long shot).
Note: pack this on the top of your pannier, 'cos it is the one set of stuff you will want in a rush.
(1) Lightweight Rain Jacket and Pants. Gore-tex or other waterproof-breathable equivalent. My personal pick is Marmot Precip, since it is cheaper but solidly made. I've gotten really rained on a few times in it and had no problems. The rain jacket seems redundant with the yellow biking jacket, above, but raingear just doesn't breathe that well, making it unpleasant when raining.
(2) Shoe covers. Gore-tex or other waterproof breathable. I spent a long while researching this -- it seems like no shoe cover is perfect -- and went with the Gore Bike Wear "Race Power" ones. More expensive, but they worked well.
Don't forget to bring a leg tie for when you're wearing rain pants. I use mine to hold my rolled-up rain pants so they are always together.
C. Off-bike Clothes.
I brought one other set of off-bike clothes, a pair of nylon travel pants and a loose-fitting loose-woven cotton long-sleeve shirt (actually I brought two, but if I were going again, I'd only bring one).
Flip-flops (Chaco Flips . . . so comfortable. I lost them along the way and paid way too much for a replacement pair in Switzerland).
My wife said her favorite piece of off-bike clothing was a stretch cotton black skirt, which was easy to put on over bike shorts in the middle of the day (for lunch or shopping) to look more normal.
D. Warm Clothes.
(1) A pair of polyester long underwear.
(2) Patagonia down jacket (or "down sweater" as they call it). This is, I think, my favorite article of clothing. Super-light, super warm. Doubles as a pillow.
(3) Arm warmers. My wife also brought leg warmers since she gets cold. Merino wool is nice.
Washing and drying
In terms of washing and drying, we just brought a baggie of detergent, or I'd often just use soap. When we arrived wherever we were staying (campgrounds, hotels, B&Bs), we washed it pretty soon after arriving, just making that part of daily ritual like brushing your teeth or showering. Often I'd just bring clothes into the shower and wash them there. Usually things dried out by morning. If they didn't we'd either strap them on to the outside of our bags, or if they were only damp, just wear them. Polyester dries out pretty fast, and you warm up while riding, which speeds it along. About every 7-10 days we'd find a laundromat (or use friends' washing machines when we stayed with them) on a rest day and wash our clothes there to get them all thoroughly clean.
I use a dry bag to wash clothes, because I often stay in National Parks campgrounds with no sinks. The Campsuds referenced earlier can be added with some water from a spigot or pump and the clothes squeezed and shaken right in the bag. Dump water, squeeze excess and add clean water to rinse. Dirty dry clothes can be stored in the dry bag until you can wash them. I also bring two sets of cotton socks, which I wear in my regular sneakers (in which I also ride) around camp to dry out rain soaked sneakers.
I toured in pretty warm weather (some mornings were in the 50s (°F)) with two sets of on-bike clothes, two sets of off-bike clothes, a jacket, a pair of tights, and a smartwool long undershirt. I left the raingear at home and got lucky. My off-bike clothes were the lightest I could find—thin T-shirts, convertible trousers made of synthetics.
For shoes, I had my cleats, a minimal pair of sneakers, and a pair of flipflops, which were nice to have along.
For cleaning, I'd rinse out whatever on-bike clothes I wore that day and wring them dry in a towel. Whenever I stayed with a Warm Showers host (speaking of which, get hooked up with Warm Showers), they'd let me use their washer and dryer.