When I first started selling masks, I went with the most popular shape, the Olson. I prefered it because the curved front allows more room for breathing, and doesn't touch the face as much as the surgeon's style. The pockets were easy and effective. The shape suits most faces, although with time I found it to be a bit wide for my buyers, particularly women.
On YouTube, I discovered a new pattern which many of the producers call the Best Fit Mask. Like the Olson, the convex shape allows breathing room, but the sharper angle provides a tighter fit across the bridge of the nose, so less of a gap. In addition, the width, which is narrower than the Olson's seems to prevent air gaps. After testing on friends, I've decided this is going to be the standard shape from now on. If you've ordered Olson masks from me and prefer them, just let me know to use that pattern for your masks. Here's a couple shots of local friends in the newer shape, and newly-added fabric option--dark denim, and blue tile.