It is best to take a moderate hit not one that is going to make you cough before you want to exhale and one that does not feel like anything. This will be different for every person. Also, when you hold the smoke in you should only do so for 3 or 4 seconds because after that time you have absorbed the most of the useful chemicals. Unless you smoking keeph of hash then hold it in till there is no more smoke. All of this is if you don't want to hurt your lungs and lose brain cells due to lack of oxygen.