Retainer, and pay in full or three payments?

[Debra Jones]

I am slowly working my way out of three digit sales and into my first four digit commission.

I know they need an oil, for the subject and detail, but I offer watercolor and pastel for a slightly lower fee and would like the commission. I had a really good price structure for oil: retainer of 30% for materials and my time and design work, at approval of detailed tonal underpainting, the second third. The final would be upon approval and acceptance of the finished piece.

First third is NON refundable. That is part of my marketing:
I am doing a promotion which I really believe in, that any of my charities who refer a client will receive half my deposit (15%) IN A CHECK TO THEM from the client, so they both benefit. I get a value of full price for my work but discount the donation. Charity gets money, client gets tax deduction! With nothing else, I think it is good, cheap advertising!

Only this first big commission thinks he wants a watercolor.

I have not quite figured out at what point the second payment should come. A small color sketch? A detailed pencil rendering of the heads? I liked my tonal sketch in oil but I work very paint by number in watercolor and it is a DO IT or die sort of thing... not much correction when I get going. Not the sort of thing I really want a client tweaking.

So how do any of you who offer watercolor work set up your pricing and receipt of monies or billing? I am willing to adjust my painting style but it is very hard to discern a stopping point before the one of no return.
dj*