That's a very open-ended question. There are lots of existing threads asking for general API advice on best recommendations. In general, the most often recommended are: If your sheet has a companion script, this is a must. It will add very specific things to make your life easier. Token-mod is the Swiss Army knife of scripts. If you can do it manually with a token, you can almost certainly automadte it with token mod: rotate, resize, auras, vision, light, layer, position, size visibility of elements, statuses and more. ChatSetAttr does for characters what token-mod does for characters. It's a bit more advanced, and you can probably do without it as a beginner, but you'll probably come up with some problem it will be the solution for. GroupInitiative is a big help. Rolls and sends initiatives to the tracker, customizable by system Groupcheck has a lot of utility, allowing you to roll a similar roll on a whole lot of tokens at once: ex. Fireball saves. Turn Tracker, TrackerJacker and CombatTracker all do similar things of managing turn order and action, but each has a different approach and different features. Roll20AM gives you a lot of environmental control that the Jukebox lacks facility with. It works well with Token-mod for doing complicated multi-step macros. I would suggest looking through the Stupid Tricks thread for ideas, since a lot of them use some common API scripts.
