As a beginner you may be better served concentrating on some fundamental skills rather than air consumption. Most beginners carry way too much lead. It’s important to be properly weighted with minimal air in your BC at depth. Work on your trim and position in the water column (without fiddling with your BC inflator). Slow down. Focus on the dive and your surroundings. Most beginners are easily distracted. Moreover, they are in perpetual motion with bicycling legs, flailing arms, waving hands and pivoting heads. Be calm, relaxed and in control. By default, addressing these basic skills will improve your air consumption. Unfortunately, I was completely oblivious as a newbie. You can concentrate on breathing more effectively, deeply and efficiently AFTER you become a more experienced and confident diver. Good luck!
I agree completely, I was actually under-waited for this dive in a full 7mm, hood, gloves. I used zero air in my BC the entire dive and I was neutral at the start, but positive at the end (AL tank) with 14lbs in a hydros. My main focus is trim, finning techniques, and controlling subtle changes in depth (rocks, structures, etc...) with my breathing. On this dive I was doing frog kick only, with as little movement as possible with the exception of a few times I had to adjust the reel the dive flag was on.
I am actually discussing with my LDS to exchange the hydros for a diverite plate and harness, and seeing if they can get an oxycheq wing. Next plan is GUE Fundamentals so I need to build towards that and get more dives in. Before the end of the month I'll have my nitrox as well.