Most beginner 3D artists have a hard time with character animation. Animation in general is not a skill you pick up easily. The best thing to do? Practice, just like anything.
A few common mistakes that are seen among amateurs:
- Natural poses
- Ambient motion
Many rookies make the accidental mistake of fast animation when rendered, caused by lagging 3D view animation. An easy fix for this is opening a timeline, and checking Playback > Frame Dropping. This will play frames at the frame-rate required skipping them when needed. If you do run into this problem, you can easily change the speed of an animation later, by scaling the curves in the Graph Editor.
The other problem is mixed speeds. Animating a walk cycle that is very fast, then animating the next section too slow, will make changing speeds later much harder. The only answer to this is a painstakingly slow process of selecting chunks of the animation and scaling them to match a natural speed. You can avoid this is if you make sure that the last section of animation matches the current section.
Timing also effects...
Flow is another important element in animation. Sections of an animation that do not flow into each other, will look choppy and unnatural. There is no easy fix for this, the best thing to do, is to watch the transition between the two motions and try to make it as clean as possible.
Natural poses are important to animation, but it is more important to great poses when you are doing stills:
(It took 10 minutes to find this pose!)
Its not great, but its better than this:
(This pose took about 10 seconds to do)
One thing you can do that sometimes helps is to look at images and videos as pose references.
A huge problem with most walk/run cycles is sliding. So many animations have walkers and runners that slide, and its not even hard to fix!!! As long as you are using a path(which makes animation easier anyway) you can easily prevent sliding by adjusting frames slider.
What I mean by ambient motion is subtle natural motion such as scratch, stretching, looking around, etc.
Good animation is full of ambient motion, and makes the character feel more real.
And that's it. If you have animating tips, post them in the comments below. Thanks!