Working as a bank teller, I've seen firsthand how fees can quietly drain people's accounts. Honestly, most customers don't realize how much they're actually paying until we point it out during a conversation. Let me share what I've learned from years behind the counter about the sneaky charges everyone should watch out for.

First thing: understand your account minimums. I can't tell you how many times someone gets hit with a fee because they didn't read the fine print about how much they need to keep in their account. The solution? Look for accounts with no minimum balance requirements, or set up direct deposit with your employer—a lot of banks will waive fees if your paycheck goes straight in.

Overdraft fees are brutal. These typically run about $35 per transaction and they add up fast. People come to my window confused about why they got charged when they were only a few dollars short. The best move is finding a bank that offers fee-free overdraft options. And here's a pro tip from my experience: if you do overdraft, call and ask for the fee to be reversed. It works more often than you'd think. I also recommend setting up balance alerts so you get notified when things get tight.

Now, NSF fees are different from overdraft fees—this is where it gets confusing. NSF happens when your bank rejects a transaction because you don't have enough funds, usually around $34 per declined transaction. Overdraft is when they let it go through anyway and charge you. Either way, keep close watch on your balance.

Dormant accounts are another trap. If you've got old accounts sitting around, inactivity fees might be eating away at them. Seriously, take five minutes and close any accounts you're not using.

Then there's the monthly account maintenance fee—usually between $5 and $12. Some banks charge this just for existing. You can often get it waived by keeping a certain balance, but if that's not realistic for you, plenty of free banking options exist now.

ATM fees are annoying too. Using an out-of-network machine can cost you $5.50 when both your bank and the ATM operator charge. Stick to your bank's network when you can. Some accounts offer ATM fee reimbursement, which is worth looking for.

Last one: foreign transaction fees. If you travel or shop internationally, these range from 2-4% of each purchase. Shop around for banks that don't charge for international transactions.

Honestly, the biggest takeaway from my teller perspective is this—read your account terms before signing up. I see people frustrated all the time because they didn't know what they were getting into. If your current bank isn't working for you, switch. Your financial goals matter more than staying loyal to a bank that's nickel-and-diming you.