I've always done the mouth-hit, (just like analogs) then inhale since I started vaping. I just (today) got my first upgrade from cigalikes. Got the smoktech ego tank with dual coil carts from Madvapes. So far, so good but didn't seem to produce much vapor on exhale and seemed to be harsher TH.
After reading this thread I've been hitting it directly into my lungs with some air. (Kinda like hitting a doob)

WOW! Much more satisfying hit! Cooler, and much more vapor on exhale. This really surprised me. I'm glad I checked out this thread.