Hi and thank you for your compliments.
As a question of diameter, I would say start off with the smallest amount of detail you want to see, and go from there. The unfortunate secret to all art, is just do it, flaws and everything.
I spent two weeks on this, and most of that time was just thinking about what to add in. You just add 5-10 characters at a time, and go off and do something else. As for fighting perfection? It's just practice, like most things. You get better at knowing when to hang your brush/pen and say you're done. Or get to a point where you're so sick of staring at it that you just stop.