I just pumped up my tire, and then ripped off the valve when trying to take the chuck off, and consequently the air.
I've learned that I shouldn't twist when trying to remove the chuck, but what else can I do to make it easier?
Ripping off the valve is a pretty rare occurence I think. If you manage to pull the valve off or even just spring a leak while removing the chuck then the inside of the rim (where the root of valve connects to the innertube and hits the inside of the rim) could be too sharp or the protective rim tape could be damaged or mis-aligned. This is the first thing I'd check.