I find the best way to do fights is to be creative. Have your characters move around a lot, use lots of different blocks/punches/kicks, just see where your imagination takes it. When I made the fight in this I didn't know exactly what was going to happen. But you may think on a certain frame 'Oh, it'd look good if he did such and such now, his arms in the right place'. Just try to keep it at the same speed, people won't like it if it has really slow animation as well as really fast animation. But your test was okay I thought. Try to move the characters around more, have them step back, step forward, fall over, just so it stops the fight from being in a fixed spot.
Also, I can't remember who it was, but a while back someone made a brilliant tutorial on animating fights in brickfilms. It got posted here, have a look and you might find it, I can't remember where it was, I've tried looking. Someone will have the link though.

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