Credit Advice

That's a funny situation.  The FICO is a meaningless score in all realms except when it comes to qualifying for a loan, thus taking on debt.  If you have no plan to take on debt, then what does a FICO matter?  If I had to guess, I'd say that you cared about your score for future reasons, such as real estate loans.  Because of that, you will need a "credit history", not debt.  Not defaulting on a loan in the past simply because you haven't had a loan is not going to raise a FICO or satisfy a lender in the future.  The FICO takes all sorts of things into play and future lenders will want to see that you had credit available, didn't overspend, and paid on time.  I wouldn't recommend doing anything out of the normal, but perhaps next time you make a planned purchase over $500, you put it on credit and pay it off in full after a cycle or two.  It will likely cost you a few bucks in interest, but it will be a good standing account on your credit history.  Car loans are something we all eventually need, so keep your credit clean and buy something in your budget at some point when you can.  Also, store cards, credit cards, etc. will eventually raise your score and show up as accounts in good standing even if you pay in full every month.  You just need more cards to do the work of a car or house.  But, the paradox is that you need credit from mortgages, etc. in your history in order to qualify for mortgages with ease.  

You want to keep in mind that it isn't good to carry a balance of more than 30% of the available credit on any card, higher percentages will lower your score.  Just charging a few dollars every month and paying it off every month will show activity and a positive payment history and will raise your score over time. It's a good idea when buying a car, even if you have the cash, to finance part of it and pay it off over time to get a better mix of credit.  Another idea is to take out a personal loan for a small amount and pay that off over time, you don't even have to spend it, just deposit it into an interest bearing account, The key is to not overspend, to stay within you budget, make on time payments and not use credit cards for larger purchases, the interest is usually higher and if you go above the 30% mark it affects your credit negatively.