good animation - know your principles
good acting - fits the plate it's on
good action - so it feels real. so a cat walks across a talbe like a cat, a dog walks like a dog
good attention to detail - all the little intricacies and details in the real world (cat's scrunching nose) how toes spread when landing (of a cat) good polished animation
power of reference
find it and shoot it (yourself if you can't get an animal to do it)
he's pro w/ 14 years but if he just knocked out a dog walk and compared it to life it would be missing something. Like drawing a self portrait from memory, instead of from a mirror. Be humble, accept that you need reference. (slow mo often very helpful, smaller animals are often too fast to see)
shoot ref of cat walking and sitting, but also of yourself to get acting beats and timing you wanted
make it happen, don't let a rig hold you back from recreating what a real animal could do
head, neck and tail on world orient (so hips bouncing doesn't wig tail out, chest turns, head still acts where you want it)
just because you have controls doesn't mean you have to use them
he animates foot/palm into place first, then corrects wrist/heel
breathing trick: grab all spine scale them all a tiny bit (expand relax chest), then offset depth first then width, then offset the different spine ctrls from each other, then sometimes animate shoulders reacting to the chest