I spam Lloid to put pressure on my opponent. Every second of the game I have Lloid out. I full hop fair to catch people jumping over Lloid, but sometimes I stay grounded after Lloid is out and try to grab them if they shield or roll through. When I go aggressive I use dair. It's a great move I feel, especially when used in conjunction with Lloid assuming they don't double jump over.
I find timber to be most useful when the opponent is someone who recovers low. If they are sent far and I'm near the edge already, I often find time to plant and chop a tree over the ledge. I think that it is better than dropping the bowling ball due to the tree's bigger size and slower falling speed. If I can set this up, it almost always results in a kill on someone like mario or link. Still experimenting with using the tree in the neutral game.
For KO moves, I like dtilt, utilt, and up smash. The problem is these are punishable moves, so I don't try to force them. Ofentimes I will kill with a three turnip dair or uair, which is safer but less reliable. Lastly, I agree with Indigo Jeans on ftilt; you should try to space it well. It is a good move to punish opponents as it is pretty quick to come out and has nice range.