Here's a tip I didn't see yet: When you first rack your beer into the keg and put the top back on, connect your CO2 and hit the keg with 30psi. This will help seal your lid better. Vent the keg and repeat 3 more times. This will help purge oxygen from the top of the keg and replace the head space with CO2. Then, after venting that fourth time, set your keg to desired carbonating pressure. I am a big fan of the set and forget method.
One other tip...always do a soap bubble leak check of your keg after its filled and pressurized for carbing. You don't want to lose precious CO2 because the keg has a small leak from a fitting.