I've been meaning to do this since I started officiating two years ago, and finally got around to it. This might help newer officials, whether you're going to be a referee or not.
I purchased one of those wristbands that quarterbacks wear that has a clear pocket where they can put a card with the plays on it:
Then I made up a card with lists of the 5 yard penalties, 5 yard penalties with a loss of down, 10 yard penalties, 15 yard penalties and disqualification penalties (all NFHS rules).
The wristband is black, so it goes with our whole look, and while the card I carry in my shirt pocket has the list of penalties and signals, I don't want to look silly by pulling the card out, checking what a penalty is, and having to put it back in my pocket. So now I can just look down quickly, make sure I have the distance on the penalty correct, and go from there.
I'm normally a linesman, but all members of a crew are responsible for penalty enforcement and if you call it, you should know how to enforce it.
You can
download the card for yourself if you like, print it on card stock, and do the same thing.
I wish I could get more info on the card, stuff that confuses me like PSK and basic spots and stuff, and maybe I'll play with it some more eventually and get to that point. For now, I'm just sharing this with anyone who thinks it might help them learn/remember penalties if they're still new to this.