Pay it off each month. Full stop.

It is WAY too easy to tell yourself, oh, I'll just pay half now and then next month I'll finish it off. Next month comes and your car is in the shop, gotta put that on the card. Ok well I'll just take an extra month, no biggie. The interest piles on, and then your job has a glitch with payroll, it'll take an extra 3 days to get paid. Now you need to put your phone bill on there. It is a slippery slope that catches a lot of people in the trap of debt.

I'm even in the habit of charging something, then going home and paying it off that day. I only use cards for points/miles.