Also, in adverse circumstances, harm can pile up faster and higher if you have your bills set to auto-pay. In the US, banks typically charge an overdraft fee for every transaction that overdraws an account, so unless you keep a generous liquid cushion in your checking account, one mistake on anyone's part (perhaps yours, or ACH, or your payee's autopay sytem, or your employer's payroll, or your other bank, or the person who stole your debit card) could put you hundreds of dollars in the hole.

To avoid this, you need to know that you have enough at the correct time in the correct place, and if you're doing that, you might as well click through each payment yourself.

If you're in a tough spot, this also gives you the option to make partial payments against credit cards and incur some interest, which is almost universally a smarter choice than incurring an overdraft charge against your bank account.