If you don't exactly know what qualifies a pair of jeans as "mom jeans," look for a very long zipper like the one in this pair:
Try your jeans on and decide about what length you would like them to be. I suggest keeping them a little longer so you are able to roll them up and cuff the ends. Mark your desired length with a pen and cut!
And there you go! A cute pair of shorts.
Currently listening to:
I got another pair of jeans to make into shorts, but I think I'm going to jazz them up a little more than this pair. Stay tuned for another DIY soon!