I use Austrailian Organics strip wax (in a plastic tub) and i use my client's microwave to heat the wax up so it's pliable for about 3 - 4 minutes and check it every 45 ish seconds (so it's not runny runny liquid) then i drop it in my heater whilst i'm setting up.
I am aware that microwaving can cause hot spots, so i always always stir my wax throughly before i start and check the temperature on my wrist before starting.
At the end of my client, i drop the lid on the tub. wrap the pot in grease proof paper, and wrap it in a towel, and then, if i'm moving on to another wax, it retains its heat enough that it only takes about 5 - 10 minutes to warm up.
I always wax first, as i think other treatments like a manicure / pedicure or facial are the relaxation treat the client needs after waxing.
Rebecca