The thing with Judo, or really Toribash in general, is that there's nothing to teach. Once you know the basics of the game, it's up to you to figure out how to meld the basics together to create more advanced moves and tactics. The best way to learn is to play, and experiment. Don't look to win, look to try new things and you'll figure out what works and what doesn't.
Also, try to branch out. Don't just play Judo, try some other mods and maybe you'll find something that you're better at than you thought. Don't get discouraged by people telling you that you suck or you're a noob either. I mean, you will, and you are, but you'll get better.
The best tip I can give you is to learn the basics. The rest is up to you.