Most of the time it requires making a deposit or withdrawal from your account, getting the teller's name and description, observing the condition of the drive through, if there are posters or pamphlets in the drive through observing them and how well pamphlets are stocked, sometimes you may have specified questions of the teller such as current rates on CDs or whether they have a rewards credit/debit card. They vary as much as any bank shops but you generally have to be absolutely on top of timings, how many lanes are open, how many cars in the lanes, etc. They don't usually pay much because they take so little time, despite the number of observations.
Key tricks to drive thru--go to the lane closest to the building as you will have the best chance of seeing a name plate or name tag or getting a description. The speaker is also more likely to work at that lane so you can hear what is said rather than just hearing "Golombenboiedgnbhoi?" Ignore the sign that says "Commercial Accounts Only" to get in the lane closest to the teller--better to apologize for not seeing the sign than being out in the boonies where the speaker is yucky. Don't go on Friday as that is when workers living paycheck to paycheck get paid and need to cash their check. Try to avoid lunch hours and right when work is letting out because that is when employees do personal banking or take the small office's deposit on their way home. Turn off your radio.