Brooks mentioned a problem which came up when he was doing "Suicide Kings." The original gig was supposed to be several weeks, then it bounced back and forth until it finally was a three-day commitment from the production company. He set up another gig to immediately follow the three days, and everyone had heartburn over it when he left.
I solved the early-go problem a few years back.
When I start a time-limited project of any sort, I tell them up front that, since they are saying that I will be finished on a particular day, I will consider myself available for other work starting the day after -- then I offering the option of paying me a daily fee (and continued expenses) to hold off. They pay by the week at a time, with at least a week's notice.
If they don't work me, I get a week off on partial pay. If they work me on any particular day, the fee for that day is rolled into the day's pay. If they want me onsite all day in case they need me, the fee is higher than if they just need me on call with an hour's notice, and that's higher than if I just have to check in to see if I'm needed the next day. Fees are negotiable, depending on location (if it was daily check-in someplace like Hawai'i, I'd just take room and board) and how much work was available.
This makes everyone happy. They know at the outset that if they don't want to pay a "deposit," I may be unavailable for extra work. If they want flexibility, they can get it without breaking the bank. Yes, I could make more if I jumped right to the next job than if I just get the standby pay, but this depends on other factors -- I'll take the known money AND keeping the people who hire me happy.
Just an idea, I dunno if it will work for anyone else but it's done fine for me for quite a while.