Using Tamiya Acylic, my brush can usually sit for about 30>45 minutes before clogging - if it does a couple of full air / paint trigger presses or nozzel wipe with meths usually clears it.
If I am putting down multiple coats of the same paint, I will usually turn my compressor up to max & air dry the first coat before going straight onto the second - I have read that this isnt the best practice, but so far it has not caused any problems.
Another thing I have noticed makes a big difference is using a cap or cover on the paint cup, this also makes clean up easier as well. If you use a cover, the remnants of paint that line the inside of the cup will stay liquid for some time, whereas they will dry straight away without a cover.
All this works well, apart from with Future - which dosen't really like being "blow dried" & gum's up pretty quickly - you cant win em all.