Here's the final version of my Stewie Tennis Camp shot, which I completed in AM Class 6.
I made a frames-to-seconds chart and used Audacity to line up the sound effects after the timing was locked down. Incidentally, I later applied a 2 frame delay to get the audio to sound right. It is always best to animate to audio without a time offset, but when everything's done and over with, putting in that slight 1-2 frame delay does sometimes sound better, especially when it's a given that the camera is a bit of a distance from the subjects. Sound travels 340.29 meters per second, or just over 14 meters per frame / about 42 feet per frame. A tennis court is 39 feet from net to rear, 78 feet in total length - the assumed distance-to-camera in this shot. So, strange as it may seem, a 2 frame sound delay for this particular scene is pretty much spot-on.
Introducing audio also led to introducing a third unseen character: Pro's opponent. in keeping with Pro's girl-power, it only seemed logical that she would be besting a man, to boot. (Who knows where Kid's balls are coming from! Whoever or whatever, the source remains silent and unnoticed.)
Frames 100 - 200 were scrapped and re-done three times over before I finally got that part right. Ironic that the very segment where "nothing in particular" was happening posed a particular challenge. But then again, thinking in such a manner was perhaps the fundamental problem with that segment to begin with. Generally speaking, no moment should be dramatically vacant. "Something in particular" does now happen there, a series of subtle but clear emotional beats.
Getting the hand-held camera to feel right took a few passes. It was initially over-active and jittery. While this may have been truer to life, it was distracting; hand-held action is best kept low-key.