I've been struggling with proportions and sketching small like this has been a huge help in rethinking my approach. I have begun drawing again after about a decade away and I went right into it with frustrating results. My proportions were always off, eyes too far from the nose, chins stretched or smoothed and head width constantly fluctuating, no matter how many times I tried to measure and sight it always got away from me. Sketching in this small format has been a great help! Thank you!