Tiago Forte, writing in Building a Second Brain, has a nifty name for individual pieces of your work: intermediate packets.
The idea here has two parts. One is that you can break down a large project into smaller, more manageable chunks. Writing a 50,000 word book might sound daunting. Writing 50 pieces of 1000 words each, one at a time seems much more doable.
Two is that thinking of these pieces as packets reminds you that you can mix, mash up, assemble, recycle, and send these pieces at any time.
When I ran an editing company and we started a PR or advertising campaign, we’d use this concept by keeping a file of marketing collateral. Images, quotations, descriptions, and so on would all be kept in one place to be reused, especially the stuff that had turned out to be effective. When the time came to assemble an awards application package, it took about a third of the estimated time to complete, because we had everything to hand.
Your interests (or job tasks) over time are likely to be related and/or overlapping. Rather than starting from zero each time, set up a decent, simple filing system (like one using PARA) is a good investment.