all practise..all practise..
i suggest you to go to singleplayer and watch what each bodypart does with different conditions (relax, contract, extend) Then you start try doing tricks and over time faster and faster. You just cant do those moves when you have only played 1 day. I had same problem, i didnt have enough time, i lost very many times, but i just looked other fighters and some teached me too something. Forums on that website is pretty helpful place.
Ok i put some replays from myself too: these are all made in singleplayer