Online I like to use 2,1,3 to punish whiffs because it is easy to remember and can be repeated at least 3 times, 4 in the corner. At the end of it I like to do a flying kick to add damage. 2,1,3 repeated three times pluse flying kick is 31% damage on its own. After doing 2,1,3 two times you can use b3,1,2 and add that to the combo, not sure how much damage it does. When they are just blocking low I use 2,1,3 and if they are blocking high I use b3,1,2. When people get aggressive and jump at me a lot I like to use bicycle kick or parry depending on how much time I have. Low fireballs are good but against good ranging characters I like to dash and block to advance. Jumping with Liu Kang often leaves me vulnerable and doesn't accomplish much for me. I try to be really aggressive but sitting back and countering their combos works just fine for me too. Hope this helps, sorry for it being such a long post.
Btw, my PSN is O_O-_-_-_-_-_-3 if anyone is interested. Pretty crappy gamertag lol
