A friend of mine, Tom Ayers, from Sommbeer.com just wrote an article...soon to be a set of articles about how to formulate beer recipes.
Check out the first one, on malt/grain: https://sommbeer.com/2019/06/04/reci...erssimplified/

It's not like any other article I've read yet, which is fun.
Cheers and good luck recipe making!