I tell them that I've been focused primarily in the past couple of years on commercial (paid) work, my regular work, and writing and marketing for the book. But I ask them to send details about the production and the schedule and I tell them I'll look it over and get back to them promptly.
Then nine times out of ten I determine that's it's not for me. It might require more time and attention than I can give in the face of my other commitments. Or maybe it's a script or role that doesn't particularly excite me. Or it just doesn't hold enough challenge or opportunity to make it worthwhile.
It's not all about me, of course. I do consider whether I might want to do it as a favor to the director or the company. But in the end, yes, it has to be about me and what's in my interest.
When I decline, I'm courteous. I thank them for thinking of me, I compliment the script if I sincerely like it, I explain that my schedule precludes my participation, and I wish them well with the production.
And then ... nothing. I know they're disappointed. I know they have to focus on the production and immediately turn their attention to their next prospect, but it's just funny -- the contrast between their initial enthusiastic implorations and their subsequent silence.
It makes you feel like the whole thing was just a generic transaction, rather than the outcome of a true and respectful relationship.
Hey, it's a business. I don't take it personally. But I don't forget, either ...