New credit card rules kick into effect today that overhaul some of the sleaziest bank practices as we know them and offer new protections to millions of American households struggling with, on average, $8,000 in credit card debt. Thanks to legislation known as the CARD Act, rate hikes will be harder to implement, young people will no longer be offered credit cards that they obviously can’t afford, and everyone will clearly see how long it will take to pay off a card if they pay just the minimums.

1. Ends over-the-limit fees. Card companies can no longer charge you fees for going over your credit limit unless you notify them in writing that you’d like to be allowed to spend more. If you don’t “opt-in” to go over your limit, your credit card will be denied once you’ve reached your allotted amount. (Don’t opt in to spend more than your limit.)
2. Requires full disclosure about what your debt will cost you. Banks have to tell you on your statement how long it will take you (and how much it will cost, with interest) if you only make the minimum payment.
3. Makes it harder for people under 21 to get credit cards. Today people under 21 will need a parent to co-sign order to get a card or they’ll have to prove they’ve got the financial means to afford one.
4. Ends shady marketing practices on college campuses. Card companies are no longer allowed to offer incentives (like a free Frisbee, radio, or T-shirt) on college campuses to lure people into getting a credit card.
5. Bans surprise rate hikes. Banks can no longer raise interest rates on debt you’ve already racked up. (They can, however, raise rates on existing debt if you’re more than 60 days late.)
6. Stops banks from penalizing you for being late on other loans. Under the old rules, if you made a late payment to Bank #1, Bank # 2 could raise your rates—even if you’d always paid Bank #2 on-time! Fortunately, this practice is now prohibited.
7. Prevents banks from staggering payments. If you had two different interest rates on a balance (say 3% for a balance transfer, and 16 % for existing balances) banks used to be able to apply your payments to the lower rate debt, meaning it would take you longer to pay off your balance. Starting today, banks must apply your payments to the debt carrying the highest rates (i.e., the 16%) first.

Here are five tips to use cards wisely:

1. Open your mail. So many people don’t—but that’s how the credit card companies will alert you to changes to your account. (They can contact you via email if you’ve previously given consent, but they’re not bound to contact you that way. So read everything.)
2. Don’t opt-in to overspend. As part of the new rules, banks will be asking consumers if they want to “opt in” to spend to more than their current credit limits. Make sure to say no so that you don’t fall into major debt troubles.
3. Watch for new annual fees. For years, these were out of vogue, but banks are starting to institute them to make up for their anticipated loss of revenue due to the new rules.
4. Watch your limits. The new rules don’t stop banks from slashing your credit limit, which can affect your credit score. Keep taps on how much debt you’re allowed to take on, and make sure you’re under your limit. A good rule of thumb is to use less than 10% of the credit that’s available to you. .
5. Pay on time. Banks used to be able to hike interest rates on your debt immediately if you made just one late payment. The new rules say that you have to be more than 60 days late before they can do that. Still, it’s important to pay on time to preserve your credit score and get the best deals.

The Takeaway? New rules haven’t changed the bottom line for using credit cards wisely: pay on-time, and only buy what you can afford to pay off in full at the end of the month.