Contrary to popular opinion - inhale, exhale, inhale, exhale, inhale, exhale.
As you're exhaling vapor (or smoke I guess) your body has processed as much of what you can inhale... but then you inhale again and it'd be pretty weird to assume that whatever is left is exempt, especially if you're rebreathing in some of what you're exhaling.
But if you really want to get higher and be more efficient with your herb switch to vaporization. Heat much above 450F just completely eviscerate the molecules that are working to get us high, so the best thing you can do for your herb is to vaporize it between 360F-420F (or 445f only with high airflow convection vapes), get mid-sized inhales and rebreath them 3-4 times gently. For someone with a low tolerance this will get them noticeably more stoned from "a single hit" since you're getting ~<85% of what you would from smoking the same thing.
Bonus: vaporization is decarboxylation so you get to use the vaped herb as edibles