1) First, choose a recipe you love. Your cookies or muffins will probably turn out better if you like what you bake.
2) Use good ingredients and a good cookie sheet. They really make a difference.
3) Test them out on your friends and family.
4) Come up with a good name. For example: Chip, Chip, Hooray!
5) Figure out where you want to sell them. I got in trouble for selling at school, so make sure you aren’t breaking any rules..
6) Decide whether you want to invite others to participate. If it’s for charity, maybe you can get your school involved.
7) Advertise! Make a poster. Send out emails to friends, teachers, parents’ friends, etc, 
8) Don’t eat the profits! (I had to hide my cookies from my family.)