Ideal is to hit it with light sand to more or less prep the surface if bare alloy. media blasting with glass contaminates the surface so don't do that. after that wash it, preheat it to cook off anything left, hit it with a tack cloth, shoot powder, set timer, put it in the oven (discuss with wife/GF as per how to use an oven), pull it out when you hear the alarm, let cool which allows it to out gas and smooth.
also level the oven just like you would any other time make sure the powder has ZERO clumps and DO NOT pack or tamp it hit the hard to get areas first and shoot just enough powder to cover the part. prep and cleanliness is the absolute best chance of the least amount of crap going wrong
well I wouldn't just go do a set of wheels first time around unless you've painted before but PC is pretty damn easy.