Several banks heard from thousands of customers when they proposed charging a $5 monthly fee to use their debit cards. Most banks quickly dropped the proposed fee, but the experience still shows how important it can be to keep track of new fees when making banking decisions.

Balance-transfer fees. Several credit-card companies are now offering 0 percent balance-transfer offers for six months to 21 months, which can help you pay off a credit-card balance faster. But these cards tend to charge balance-transfer fees of 3 percent or more, which could cost $300 to transfer a $10,000 balance. Make sure you're saving enough money in interest to make the fee worthwhile. Of course, it's even less expensive to pay your credit-card bills in full and not carry a balance.

Increasing ATM fees. Using another bank's ATM could cost you $3 or more in fees from the bank that owns the ATM, and your bank may charge you a fee too, which you may not see until you get your monthly statement.

Higher annual fees for rewards cards. Getting cash back for your purchases may sound like a great deal, but the fees for rewards cards have been rising. Make sure the rewards you're getting for the fee makes sense.

Annual fees for checking accounts. More banks have started charging fees for checking accounts, especially when balances fall below a certain level. See if you can avoid the fee by boosting your balance or consolidating more than one account at the same bank.