What Is Locomotion? Could You Provide some Tips on Locomotion?
This is a huge topic to cover with one post. Locomotion is the means or effort of moving your character through the scene under his own power. Any movement being done like walking, running, crawling, swimming, skipping, dancing, climbing etc is locomotion. And locomotion is dependent on gravity and weight. And will change in space, underwater, in wind, with inertia, friction or if the character is hindered by restrictions, baggage or injury.
http://en.wikipedia.org/wiki/Animal_locomotion
The mechanics of locomotion and how you break it down totally depends on the character. A dog, a bird, and a human all will move completely differently, and a human like Ms. Incredible moves a lot different then Edna Mode due to proportions. And that is the same movie! First you need to get reference on what you have to move. If its a human, act it out yourself. If the character is very heavy, put on a backpack, if you can't perform how you would like, maybe a friend of yours can help.
If your character is not human, find the most comparable reference you can on the internet, movies or real life. A good place place to find animal reference is at the zoo. When you find good reference watch it over and over, and frame through it to find out how the weight shifts, and the hips and shoulders move, and the tempo of the movement.
When you actually begin animating, try to simplify. There was a shot of Horton moving though the jungle and the animator animated a simple sphere going up and down to get the timing of the body, then once he liked it, he copied the curves to the body. Then layer on top of that. If the character is simply walking or running start by creating a cycle to help yourself get started. There is a ton of info out there in books and online on how to animate walks and runs. If the character is acting while moving about the screen space, don't focus only on the mechanics of the foot placement, instead work on the key poses hitting the acting beats you want. It can be helpful to have the legs in FK or making them invisible while you pose out the body, head, and arms. Once you hit your acting beats then place your feet underneath taking the proper steps or weight shifts, you can layer on some hip shifting, more up and down with each step without taking away from the acting you have achieved.
Ed Hooks had a good tip on locomotion and acting. What is driving the character's personality? Is he very agitated or irritable and stiff, and his eyes darting around? A character like that will be leading with the head, his center very high in the body, and moving quickly, sharply, attentive. Or is it a strong masculine character? This characters center is in his chest, and animation should suggest a slow confident pull with a strong solid movement. A female character trying to seduce, maybe in the hips. A very jolly, fat character, his belly. These are all stereotypes but you get the idea. But thinking about that as you animate can help pull more personality out of the movement. It should be about mechanics but driven by personality.