Remember basic guidelines:

• avoiding manic highs and lows of spending/saving (scoring systems reward steady performance);
• don't borrow to buy depreciating assets.
•  keep a monthly budget, no matter much money you have;
• don't use credit cards to make impulse purchases;

Once you've checked your credit score and done all you can to raise it to a comfortable level, keeping it there should be relatively easy.

But these guidelines don't address some more basic questions. Like "What's a safe amount of consumer debt to carry?" And this is a good question to ask because, with all the various payments an ordinary American makes each month, it's easy to lose track of just how much you owe.

To answer the question of how much debt you can handle, use the 20/10 Rule: Never borrow more than 20 percent of your annual net income (after taxes) on credit card. And your monthly payments should never exceed 10 percent of your monthly net income.