For me, it's: 1. Pick the simplest, most trivial concept at the core of your project and implement the minimal toy version of it in a REPL. 2. Now implement t

For me, it's: 1. Pick the simplest, most trivial concept at the core of your project and implement the minimal toy version of it in a REPL. 2. Now implement the next simplest thing that moves the needle of progress. 3. Repeat. I started working on a Bitcoin implementation a few months ago to practice Clojure. It started with this: (def block0 {:hash "abc"}) (def block1 {:hash "def" :prev block0})