I had lots of problems with my upper lip.

What I do is curl that area down over my teeth, thereby expanding the area. I then do a north to south pass. It'll take practice to figure out the pressure and angle but by curling my lip in such a way, I automatically am stretching the skin while also giving me more area to work with.

Good luck! If my advice doesn't work out, keep experimenting with different facial contortions till you find one that works for you.