Not really much to talk about with this one. I find the northwestern section of the outback's wild area to work best for random drifting just for the heck of it
Works easiest with an overpowered underweight car, such as a 1974 Toyota Celica GT equipped with Don Joewon Song's tune (See Maka91's Solution for Underdog in Forza Horizon 3
), however, any car will really do.
Also, turning off the ABS, stability, traction, etc. can give an extra edge to get it done more quickly.
Anyway, easiest drifting is to just drive in a straight line through the desert and turn while accelerating after a short break or E-Break while at speed. rinse and repeat x20.