Standing in line at the bank to deposit a check is an avoidable errand. Every major US bank app - Chase, Wells Fargo, Bank of America, Capital One, Citi, USAA, Ally - has mobile check deposit built in, and the flow is nearly identical across all of them. Sign in, pick the account, type the amount, photograph both sides of the check, submit. Two minutes total.
This walkthrough uses Jenn from GOBankingRates demonstrating Chase Quick Deposit on an iPhone. The screen names and exact button labels vary by bank (Chase calls it Quick Deposit, Wells Fargo calls it Deposit Checks, Bank of America calls it Mobile Deposit), but the actions are the same. If you bank somewhere else, the steps still map cleanly.
One detail the source video glosses over deserves more weight: the endorsement. Banks now require you to write 'For mobile deposit only' beneath your signature on the back of the check. Without that exact phrase, many banks reject the deposit - and if a stolen photo of an unrestricted endorsement gets into the wrong hands, the check can be cashed again. That's step 4 below and it's the one most people skip.
Before you start: have your phone, the bank app installed, the paper check, and a pen handy. Sit somewhere with bright, even light and a dark, plain surface to lay the check on for the photos. If you already balance your account, log this deposit in your checkbook register as soon as you submit, and keep the paper check until the funds clear (usually 1-5 business days) - same rule that applies when you write a check. While you have your phone out, this is also a good moment to confirm you have a recent phone backup, since losing a phone mid-deposit is its own headache.