I am just going to re-wrap my road bike's handlebar tape tomorrow. Before I do that I was wondering what the proper place is to put the brake levers. I know they should be pointed vertically, however I was wondering if there is a rule of thumb.
In the olden days one idea was that the bottom of the levers should be along a line projected from the bottom straight section of the bars. I don know why, and that was often an uncomfortable position for me. So I am a long-term follower of the "what feels comfortable" approach.
This is connected to what angle your handlebars sit at, so it's important to get that right at the same time. If you were happy with how they were before you started, leave them there.
My first step would be to attach the brake levers to bare bars, ideally without cables (it's easier if you're doing new cables at the same time). If you have a wind trainer, put the bike in that because it will make evaluating the feel of the bike easier.
Then try the two positions that matter to me - resting on the hoods, and standing up pulling on the levers. The latter is harder because it's usually something I do on hills or in sprints, not cruising along the flat. So I focus mostly on the resting position.
Sit on the bike, rest on the hoods and see how you feel. Lift the levers a little and see if that feels better. Then drop them back. Only a few millimetres at a time. Once you have somewhere that works for you, you're done.