The main thing is not to red line when changing up all the time, if you drive hard allot. If you do this allot you will stretch all the bands and stuff your clutch packs.
If you have been driving an auto for a while you'll know and feel when you're about to change up, just back off a little then come back on the gas.
All this said, if you are going to continue modding your ride, then be prepared for it to let go. I learned this the hard way. If you're gonna go for more kw's after this I'd get it serviced and maybe get your torque converter cleaned. It's pricey but better safe than sorry.
Yeah, and a tranmission cooler is a must as Steve said.
Cheers, Byron