There's really no good tips for doing this. You have to do EVERY fight on hard in ONE basic playthrough (i don't mean sit there for hours on end one playthrough, you can do some fights, quit then come back and your progression will be saved. but you cant do any of the fights on normal or easy) a good strategy ive found is to evade alot. directional attacks are good too. also, abuse the environmental hazards. your opponent can put you in the "death state" A LOT qucker then you can get them in it, so be aware of that. also, learning to block where you grab them JUST as they attack so you grab them is also good. blocking and evading are important when playin on hard, because the AI is pretty beast.