Getting Started with Animatica

1. Install Animatica, then add a resource pack that contains OptiFine-format animations (or make your own - see Creating an Animation).
2. Enable the resource pack in Options -> Resource Packs as usual.
3. Turn the animations on. Open Options -> Video Settings and make sure the Animatica toggle is enabled (it is on by default). Toggling it reloads your packs so you can compare the animated and static look instantly.
4. That is it - any texture the pack targets now plays its animation in-game.

Animatica is client-side only. It does not need to be on a server, and it is safe to add to or remove from any setup at any time.