Build a Swipe Files of all the examples of success in a specific domain you want to conquer and tag the recurring patterns. This works great to spot recurring themes for ads that perform well (or don’t perform well). Then, you can decide what to copy and when to innovate.
Sylvain's take: ⛏️ Going Deeper: Mike shares more about why in this essay. Swipe Files work for ad creatives, but also very well for many other things (onboarding, lifecycle marketing, etc.). This is the same theme as “being a student of the game”.
For ad creative inspiration specifically, Shamanth has launched The Daily Ad newsletter and has shared a lot on the Mobile UA Show Twitter account. His team collects all of these in Airtable.

There’s no wrong way to start; you can improve it later—Miro board, Airtable, etc.