Jennifer,
I use brute force to add anticipation and overshoot.
1. Keyframe your ball from left to right (or wherever to wherever) with linear keys.
2. Select your second keyframe, copy it, move down 2 or 3 frames, and paste it.
3. Now go back to your 2nd keyframe and just slide your ball a little towards the direction you need your overshoot.
Elegant? Not really. But it works pretty well and once you get the flow down it’s pretty fast. Be sure to add a little squash and stretch with your scale or bez warp or mesh warp. Whichever fits your situation best. Fun stuff. Make sure motion blur is enabled and turned up pretty high too.
You can probably do some searches for an expression that’ll give you some of this, but this is a nice “down and dirty”.
Good luck.
Scott
ps. I like to have the first keyframe set to Ease out, 2nd one set to linear, and third set to Ease in. You’ll need to experiment to find which combo you like best.