Important note: The next time I update this collection, I'm changing the title from "Tale of Years: Prequel One-Shots and Outtakes" to "Tale of Years: Stars Along the Way." I wanted something less cumbersome and also broader, since I do occasionally include batches of headcanon like this along with the regular narrative chapters. And the new title is poetically optimistic on purpose; there's always a bittersweetness to Twilight fic which makes those moments of laughter and love and hope all the more precious. The title references Edward's line in New Moon: "Before you, Bella, my life was like a moonless night. Very dark, but there were stars—points of light and reason... And then you shot across my sky like a meteor." And that line, in turn, was the inspiration for a line in 1950 when Edward is smiling at Alice's antics: "This life might be an endless horizon of night, but even I had to admit there were stars along the way."
For this batch of headcanons, someone on Tumblr asked what the Cullens might do for their cover story beyond just going to school and work. It's all in the details!
-Most of their mail is delivered via Jenks in packages, but they also make sure to receive mail locally. They generally limit their local mail to things that line up with their current cover story: Carlisle gets a few medical journals, Esme gets things about gardening and restoring old homes, etc. The kids have a few subscriptions of their own (fashion, car shows, electronics/Popular Mechanics) but most of them are in Carlisle or Esme's names. They get their bills and the usual stuff related to their local bank accounts, a couple investments, property taxes. Maybe a couple things that link back to their current backstory, like Carlisle getting occasional alumni mail from wherever he supposedly went to medical school. Possibly student loan payment vouchers, though that's probably a bit over the top. Halfway through high school the kids start getting college junk mail.
-Speaking of bank accounts, they have accounts at a local bank with just the amount you'd expect from a fairly young doctor and a freelance restoration architect. None of their more lucrative transactions go through this bank.
-Esme takes care to be seen grocery shopping now and then. She spreads her trips over a few stores so no one is surprised if she doesn't come by for a while. She donates most of the food to churches and food banks, but never so much as to raise eyebrows.
-The most unpleasant job by far is generating a reasonable amount of trash and recycling for a household their size. This has actually gotten to be more of a challenge over the years as they find it more and more difficult to live in spots where free city pickup isn't available these days. The kids DREAD being assigned trash-generating duty. It's the most frequently traded/bet upon chore.
-All the Cullens find subtle ways to "age" over the course of their time in a certain location. It's mostly done via clothing, shoe height and hairstyles, but occasionally they'll go the extra mile with eyeglasses, "graying" hair, or even intentional changes in their posture and apparent energy level.
-It's the kids' job to be seen in town walking around, checking out little shops, studying occasionally at a café, and so on. They prefer to go have fun elsewhere (especially where they can act older, if they're playing a younger role in their hometown), but they'll hang around locally just enough so that no one ever says "Whoa, I just realized I've never seen them anywhere except school/work."
-Likewise, Carlisle and Esme have the occasional date night in town, or are at least overheard to be talking about a recent event they attended in a nearby city.
(I do think that some of these effort have dwindled over the years; it's all so repetitive and they've noticed how unobservant humans are.)