Go here:
http://www.tekkenzaibatsu.com/forums/forumdisplay.php?forumid=198
Choose your character, and their forum will have a combo thread with everyone's standard max damage bread and butter combos. You don't need to stress your brain for hours trying to come up with them, especially if you're new to Tekken. It's a lot easier when you've been playing for years and know everyone's moveset already... coming from past games its fairly obvious what the optimum juggles are, but I can imagine for a new player trying to come up with their own, it could seem overwhelming.
You generally want 3 go-to combos, and they're mostly variations on a single theme.
1. High damage solo combo
2. High damage tag assault combo
3. Long wall carry tag assault combo