if it isnt obvious where the smoke is, then maybe you're hitting the bowl/joint incorrectly to begin with, and there isnt much of any smoke in your mouth OR lungs

when you hit what you're hitting be sure you have a seal with your lips and a strong inward flow of air

you should be able to feel the smoke in your mouth and then feel it even more when it enters your lungs, its quite obvious once you know what to feel for

also, when you exhale you should see a rather thick, consistent "breathload" of smoke, not just a little puff at the beginning of the exhale