Drink less beer....
Air pressure is critical, you can over inflate them if the terrain is grippy, which will help reduce traction, thus allowing it to slide better.
Connect your sway bar, if un-connected.
Pre-load your springs, not as to raise ride height, but to help eliminate body roll.
Lower your center of gravity. My first mod was to get seat lowering bases. Sounds silly, but it was the cheapest, most effective way to lower over 400 lbs of weight in the RZR. Yes, I weigh 220 and my passengers are often near the same. Lower center of gravity makes a huge difference.
Pre-run the corner that you wish to drift.
Gas it out! If you feel the tires starting to grip and the body starting to shift, GAS IT OUT!! to break the traction, this will help eliminate the roll. If the body continues to shift over, be prepared to rapidly turn the wheel into the roll, you may pull out of it by doing so.
Run in 2wd.
Remove unnecessary weight from the bed, if you want to go hot lap, make the thing light! Take the coolers, fuel, spare tools, beer and keg out of there. A lighter less planted rear end will help it drift the corner smoothly.
Widen your wheel base, my Tokyo Drift RZR sits at about 68 to 69 inches wide. It can slide corners really well even with 32" tall tires.
Practice, Practice and more Practice!!!
Watch the movie Tokyo Drift 10 times in a row and you will be a PRO!!!!