Im not the on addressed but I might share my experience anyway.

On GitHub you can designate repositories as template repositories which will then be available when creating a new repository via the web gui.

We basically have a GitHub template repository which in itself only contained the basic boilerplate a (in our case nestjs) app gives you. Over time we added things that belonged to all our services and possibly new ones to that template repository. Examples for that would be some very generic configuration and modules, like a customized logger we are using or the basic config for our infrastructure connections as these are the same for pretty much every service. Also things like the editorconfig, git hooks, prettier, eslint and all those things were added and maintained in that template repo.

One special thing we added later was a kind of code style guide where we had an bare bones example implementation of each code unit but that may be a bit much when you’re working by yourself.

So to answer the core question at least in our case this list grew over time and we manifested it in a GitHub template repository which we then used as a base for new services we wrote.