Hopefully you have let your crepe batter sit overnight. You can skip this step, but it just won't taste as good.
The corn starch will have settled to the bottom of your mason jar. Use a fork to scrape the corn starch up and mix it back into solution.
Get your non stick frying pan hot
Add a little butter -1 tsp
Add about 1/8 cup batter
Tilt pan to so that batter evenly coats pan
Use a heat resistant spatula to release edges
Flip crepe over when batter begins to look dryer (color will lighten as it cooks)
Slide crepe off onto pan
You're looking for a nice brown on each side of the crepe (see photo)