I have started with generating very detailed "feature" spec and going over it many times until it looked good to me. Then I made it write an "architecture doc"

I have started with generating very detailed "feature" spec and going over it many times until it looked good to me. Then I made it write an "architecture doc" and plan how to implement all which was about 15 parts. Then I was making it implement one part and then tested it and made it fix 20 things and then again, and consolidate docs too, so after each part it looked and worked well enough.