Stick to 3K, P combos, 66T, 2T, 236T in between, juggle, especially if you see Holds. Go for a 3P, then Throw, or 3PP on CH if you think it's safe to a SDS then H+K into a juggle.
46P or 4PP to a 3P to pick them up
If you feel pressured, 7K or 4P or 5K or P+K or H+K
Use 16P randomly and in juggles more often, that wall damage is important
4P+K in a middle of a combo to a limbo stun, launch & juggle or 16P
Use these three at least once a round but not together, 8PP, 2K and (hold)1P+K
When you bounce them off the wall, (hold)3P and buffer into a 16P
Or
16P to bounce them off the wall and 16P again
Make H+K your failsafe move, and P+K, P, and P+K, 8P your secondary failsafe moves.
Use 1K and (hold)6K together, mix them up, follow up with 1K's P or K and (hold)6K's K, if you see Holds, Throw
44P guard break into a 8P or cancel into a throw
Use 2H+K, H+K, 33P together, but not in that order
Gen Fu is environmentally friendly,
his Strikes & Throws are all-round, use the according strikes & throws that cause more damage with the environment. He has offensive power, but short range, play him defensively. Use your parries. Understand that his moves are very linear, but mostly lead into Stuns. You're always trying to trick your foe into a Throw if you're not trying to Juggle, while using 16P in between everything.