If you can't remember to pay your credit card bill every month, Redittor SolidDexter has a solution: write the due date on the card itself.
Photo by Pixel Embargo (Shutterstock).
It's a simple but effective idea:
Assuming it's fairly static you should be able to put something like [25/n] on your credit card to know when you have to pay.
All you need is a permanent marker and a little space. You could even reserve some room next to your signature if you plan in advance. This way you'll regularly see that date and can remember to pay off your balance.
Of course, this presumes you don't want to use autopay and can't change your billing date to something impossible to forget (like the first of the month). You could also set a computer/smartphone reminder, but this is a way you can see the date regularly and actually commit it to memory without making any effort.