Just write the best you can. Its kinda like saying how do I take care of my car paint and I won’t be washing it ever again.

Get your load time as low as possible. Setup some internal links and add as much good content as you can. It seems like you want to put about 5 hrs into the site and be done , which generally isn’t how SEO works as there is pretty much always something that can be done.

So for your situation i would do as much work as you are going to do and then that’s it.