Side project habit: keep a short list of features you decided not to build yet. It keeps scope in check, and when people start asking for things, you already have a roadmap to check against.
Next.js tip: logging and analytics don't need to slow down the response. Wrap them in after() from next/server and they run once the response is done.
It works in Server Components, Server Functions, Route Handlers, and Proxy, and still runs if the request errors or redirects.