I mean offsetting your keyframes.

Offsetting your curves adds a bit of spontanuity to your animation and makes it look a bit smoother. By this i mean
if you have keys for rotation on the hip, waist, chest, head etc. on say, keyframe 50 for example. Leave your keys on frame 50 for the hips, 55 for the waist, 60, for the chest, and 65 for the head.

This is purely an example.Your timing is based on your scene. The other thing you should try and remember is contrast. Contrast in any animation adds realism. For example, you have a character strecth. And when blocking it out, you have youur right and left arm stretch in simular positions on the same key....boring. Just subtly offsetting the position and keys for that movement will add contrast.

I like your animations mate on your site.
Do you film yourself before you animate?