Warm skin is more vulnerable to damage. Prep the skin well. You want the skin to be hydrated enough to not stick to the wax. Try over prepping then pat dry with a tissue. Some waxes can be applied over a teeny smidge of oil. If that doesn't work for your wax, try adding a bit of afterwax lotion to your prewax prep (I do this for legs, with 2 pumps of prewax gel and 1/2 pump of afterwax lotion into the palm of my hand).
I really like outback organics prewax gel for prepping bikini. I never need afterwax lotion with this gel (just the cheap stuff I use on legs) Experiment on your arm to work out how the skin should feel. It should be beautifully hydrated but not wet, if that makes sense. Once you understand how skin should be prepped it makes waxing a doddle.
Alternatively, a wax like Adam and Eve hot wax, requires just a wipe over with a wet cotton pad of their prewax lotion (which is like a facial toner) combined with 1-2 drops of oil. Then hot wax. Voila. Minimal skin support required. While you work on your skill, a good product can really help you out.