The most important thing is to keep practicing, eventually you'll never even think of it. It'll just be second nature and you'll smoke very efficiently. But something I'd like to add is don't hold in hits for more than just a few seconds, that's because THC absorbs into your blood almost instantly, and after that it's just other harmful plant material that is being absorbed. This is why if you try taking a huge hit and hold it in for 10 seconds or more you'll notice that you'll exhale mush less or no smoke.