Audio-only crossfades in the whole timeline! Or add multiple sound-only dissolves at the same time to as many clips as you select.
Almost every time I edit, I need to add soft audio transitions between cuts. All of them. Even a smash cut that you WANT to be jarring can create an unwanted "pop" when the playhead jumps from one digital audio file to another.
One of the first things I learned working at CBC in the early 90's is that a 3-frame audio crossfade is the best way to smooth out a sound cut without actually making a noticeable overlap.
One of my main reasons for avoiding Final Cut X for almost two years was the difficulty of adding audio-only dissolves. In FCP 7, you could select your whole timeline, hit command-shift-t, and there you'd have it.
FCPX official workflow is to right-click->expand audio/video, then drag the ends of the audio clips each way so that they are overlapping, then drag the fade handles inwards so that the fades overlap.
GIVE ME A BREAK! For hundreds of edits?! Do I have a sign on my back that says "Please give me carpal tunnel syndrome?"
SO I've been perfecting this workflow and thanks to Alex4D, and a little poking around, I've solved it.