I usually plan up to ten sittings for a tronie and have completed five with Tony so far. Tony hadn't sat for a portrait before so I spent two sessions ( two hours per session) doing various sketches. It's important not to be anxious about the first session. If you're patient the sitter will find the right pose that you're both happy with. I was very happy with the final drawing. It took about 90 minutes spread over two sessions. I transferred the drawing with tracing paper and worked on the ink-in and poster study on the third sitting. Unfortunately Tony wore a different coloured top for the third session but luckily it was a blue hue as well as tonally appropriate. The fourth and fifth sitting I mixed up a neutral grey to mix with limited colours and turpentine for the wash.
For this work I looked at some of Rembrandt's tronie's from the late 1620's - early 30's for composition and formatting ideas.