This depends. I have a weekly income I know I want to meet to cover bills, lifestyle and a few savings. I also however have other projects to fit in which to me are equally as important. Client bookings can all come in for one day, then nothing the next few so I try and judge it as the bookings come in. The drop out rate for new clients I find to be extremely high, as much as 75% for the first booking so if I've been quite then had a lot of enquiries I may book as many as 4 in for one day and see what happens. I have gotten up to a day fully booked to find every booking drop out, not confirm or cancel, other days when they've all confirmed and I've taken it on! Other times I might not have any bookings for 3 days, or 3 one day, and 1 for the next 4 days.
So long as I meet my total for the week I'm fine, and if there's an event I am interested in or simply feel I don't want to take any more chances I'll turn any further bookings, although I may change that for a reliable regular.