Every movement makes a claim
When something slides in from the right, it tells you where it came from and where it will go when it leaves. When it fades, it tells you it was never really there. These are statements, and users read them whether we mean them or not.
I start every motion system with three verbs — arrive, respond, depart — and a single easing curve. Everything else is earned.
Restraint scales
A small vocabulary, applied consistently, beats a hundred clever one‑offs. Your motion should feel like it was written by one hand.