Editing sprite sizes without the choppiness?

I’ve just got a really simply question.
How do people shrink the sizes of their sprites (for avatars) without making them look choppy and crappy?

Im sure the answer is simple enough, but it seems like every site that provides sprites for Third Strike has them all set at a default size. But 160x64 pixels doesnt give much room to work with…


Rule of thumb: Never resize sprites.

Unless they’re Guilty Gear sprites. Those would probably be the only ones I shrink, since they’re HUGE.