I have made two different style of masks. I wanted one with both the side pleats and darts for the nose and chin. The first one was here.
https://www.instructables.com/id/AB-...se-by-a-Nurse/
It made a large mask. My husband said it was comfortable but I thought it was too big. It wanted to ride up into my eyes. I also thought the binding was too much work if I was going to make a lot of them.
The other pattern I used is from wesewgotthis.com I like this pattern, but I modified it a few ways. I use a piece of paracord for the tie. It goes down one side of the mask, around the neck and up the other side. I use a plastic cord lock so it adjusts quickly and I don't have to tie a knot behind my head.
I also join the two layers by the top and sides but hem the bottom of each layer separately. That way I can slide a filter in between if I choose. If I can figure out how to post pictures I will put some up.