Number of Revisions Limits
One of the most important things to do when negotiating a deal, especially on the “smaller” projects, is to limit the amount of revisions. A deal that at first seems really good can really become a nightmare when the client requests revision after revision. And especially the smaller gigs are very problematic on such things.
Doing a 60 second commercial for 1000$ that you will be needing approx. 5 hours for seems like a decent hourly rate at first, however if your client requests 3 revisions on it you will be spending 20 hours on it at worst which shrinks down your hourly rate to 25% of what you originally estimated.
On larger scale projects it is pretty unlikely to get that many rewrites on all cues but still then it might make sense to include a clause in the contract that limits the rounds of revisions.
A standard clause would be two revisions included in the price and any further revision will be charged at an hourly rate of X. While two revisions still might seem a lot at first, it is a quite effective psychological barrier for clients who can’t make up their minds, as effectively two rounds means one complete rewrite with adjustments which is what is reasonable for both parties.