http://www.youtube.com/watch?v=9SAKPS7BnWA&feature=related
i use this technique, 5 small hit (do not exhale), so heater is always at desired temp.
When i pack 1/3 of wand, i have to start at 10-11, but when i pack 1/5 or 1/4 i start at 12:00.
How much hit do you get depends on temp, packed bowl...