Take the centre of the ring straight away and just jab and counterpunch, dont even use your right hand until theres a decent opening. If you get onto the ropes try and counter one of thier shots and use the momentum to push away, if your in the corner then do the same, theres other things you can do like sort of half punching/half tapping their elbow, which makes them turn slightly letting you escape (its really hard to explain how to do). Best bet is not to let them cut you down and get you into the corner/ropes.