I pay almost everything with my CC including my rent (yeee Amazon points) and I pay it every month, never carrying a balance (so no interest ever). But I keep track of what I spend and I know what my usual monthly budget is. So it actually helps my spending habits because I see a hard number at the end of the month telling me what I spent.

It's actually bad to never have credit. The more credit you have and use, the better your credit rating will be. I request increases on my CC limits (I have two CCs) every couple of years and I get a couple thousand bump every time. I don't know what my FICO score is, but I think it's good.

http://i.imgur.com/81XSukd.jpg <-- Happy trails