I think this might also depends on the duration and the nature of the contract work but perhaps you can consider increasing your rate as a way of filtering out jobs when you start getting more jobs than you can handle.
This is advice I give contractor friends frequently. Too busy? Raise your rate until you are winning fewer jobs but making the same amount. Or working less for more money.
My observation having gone through this several times over 15+ years of contracting: perhaps counter-intuitively, the clients you retain and the new ones you acquire at your increased rate will treat you and your time with more respect. I don’t have a solid unifying theory on why this is beyond that your rate as compared to expectations is directly correlated with clients’ impression of your value.