Anticipation is one of the Principles of Animation, but where and when should it be used? Does every action need an anticipation? Does it really make a difference?
To answer that last question first: Absolutely. All the principles are important, of course, but anticipation has a way of getting more bang-for-your-buck than almost any other technique. The reason for this has to do with your relationship with the audience.
As an animator, your job is to entertain the audience, and one of the best ways to do that is to subconsciously lead them towards whatever comes next. As human beings, we enjoy a natural feeling of anticipation that leads to an expected outcome. The human brain rarely likes being completely surprised (horror movies aside), but even a surprise is accepted and enjoyed if there’s a little bit of warning. Any time you move a character, it pays to give a little visual-nudge to the audience and say “hey, something’s about to happen.”
You don’t have to go crazy here. Not every anticipation needs to be the textbook “wind up before the pitch” style movement.
As Mariel Cartwright explains in this video on Animation for Games, even one frame of anticipation is enough to make a difference. It’s not something that’s necessarily “seen” by the audience, but it is definitely felt. (Special thanks to Mahesh Pagar for the GDC link.)
No matter what your next animated movement is, try out a little anticipation first. Even if it’s a frame or two, experiment to see if it adds a layer of life to your shot. Usually it will, and with very little extra work on your part.
Want to expand things even further? Consider adding Intention Cues into your poses, as explained in the article “What Are Intention Cues, and How Do You Use Them?”