An easing rule of thumb

If you’re moving an object from out of the frame/stage in to the frame/stage, use an ease-out variation.

If you’re moving an object from inside the frame to outside the frame, use an ease-in variation.

If you’re moving an object from one place to another in the frame, use an ease-in-out variation

Of course, there are exceptions, but this helps with keeping animations from looking weird or “not right”.