Fun fridge magnet I created for my girlfriend, now Wife, as a joke and she said, "no, that's good advice", so here we are.

I have a couple of these I'm making as they're easily adjusted to fit whatever someone wants to say on them. There is a recessed hole for placing a neodymium magnet inside. You have to pause at 4mm and place the magnet inside. I used 12x3mm(cannot be larger than this height or diameter). Set a second height of 5.1mm to stop again to change filament, then continue. That's it. Shouldn't take more than an hour to print 1. If you didn't want to insert a neodymium magnet, you could put magnetic tape on the back. I've done that too without needing supports.