Good RAD SDLC Methods

I'm wondering what are the good Rapid Application Development SDLC's out there, and what methods do you guys use. I personally do the planning in my head, and then go straight to designing databases, then the coding, testing, and deployment. The problem with this is when other developers get my code they only get the database diagram, the code, and code comments.

I want to write the proper documentation for my projects, like for example requirements, purpose, solution, etc...