I've been learning Ruby on Rails for quite some time now and have built several toy applications. I've taken many classes/courses (i.e., Hartl, Code School, Udemy, etc.). Now I'm working on a pet project that is fairly complex - many models and relationships.
Here's my question: How do I go about thinking about a complex application in terms of models and relationships? It seems to me there should be some visual way to model all of this, but I haven't seen any discussion of such modeling in any of the classes I've taken. Sure, there's the very simple diagrams in the Rails Guides, but how do I extend this to something more complex? Or, am I making this too complicated? Do I just start coding models and relationships and see where it takes me? It seems this ad hoc approach could easily paint me into a corner where I'll have to start over from scratch if I paint myself into a corner, so to speak.
Are there tools or blog posts that can help me?
(Note: I've also posted this question at Reddit.Com/r/Rails at https://www.reddit.com/r/rails/comments/7c9zbf/how_to_think_about_rails_web_application/)