Are you smoking the same strain of bud consistantly? I know this sounds weird, but if you are then you have probably built up a tolerance to it. Try switching to a different strain, yes, even if it is it a shittier one. You may get higher off of it. I do know another smoking method you didn't have posted up, and it is the closest to a vapor style high using a bowl or bong. It's solarpuffing. Check out the link. http://www.cannabisculture.com/articles/1483.html