Make sure your bud is ground up or broken up pretty well first of all. When the vaporizer is heating up, if your bud is a little moist, the moisture will evaporate first and may fog up your vaporizer. You can take a few tokes to clear out the moisture. Most vaporizers will take for 5-10 minutes to start vaping the THC. You will see the vapors start to float and swirl off the bud. You can start to toke, but I usually wait a few until a decent amount of vapors fill up for the first hit. It will feel like you are toking warm bud flavored air. Won't hit you right up like smoke, but it will creep and be a clearer up type high. After most of the THC is used up you will see less and less with each hit and the bud will appear dark brown. With a vaporized you will have to plan ahead when you want to stop, because it will continue to vaporize for a while even after you unplug it. Good luck!