Portraits & Miniatures - Click below to create a pop-up scroll window.
For me there's a simple test, the picture either looks like the person it's intended to be or it doesn't.
Sometimes all the magic kicks in and the picture works from the start through to completion. Sometimes you have to work on it to get it right but if I ever get to a point where it's not working, I throw it away and start again.
The few miniatures I have done have been difficult but interesting challenges.