They were "fun size" bags. We rinsed them out carefully with a bit of dishsoap and then dried them. Then placed them on a cookie sheet with a sheet of tin foil and sprayed non stick cooking spray. Then put them in a 300-350 degree oven until we had the size we wanted. I don't remember how long they took though, maybe 5 minutes?
The ones that look like bowls were from a 400 degree oven batch so I would start at a low heat and slowly go up if it's taking too long.