I'm trying to figure out a reasonable percentage that I should take from the budget for producing music videos. I pretty much do everything, but do hire a small crew.

Things that I do myself are
*get the gig
*hire the crew
*direct the video
*editing the video
*producing the video
*write the treatment

Ill hire, lighting, camera op, dp etc.
So not including things like location cost or props. What % should I get and what % should I leave for hiring the crew? Crew is pretty much one day of work where my work could last weeks, planning editing etc.

Whatever your dayrate (or hourly rate) is, charge that for the things you list. When I bid a gig, I spec out how much time I expect everything to take, and I bill for that time. 4 hours to gather information, 4 hours to write a script, 4 hours to shop it around and make changes, 8 hours on set, 20 hours editing, whatever. So in this (hypothetical) example, I have 40 hours @ whatever your hourly rate is.

When I hire crew, I charge 10% on top of their rate. They get $450/day, I get $45 (that I bill the client for).

For me, this is easier than trying to decide what I think the client will pay, charging him that, and then trying to get a crew for that price. It's very ala carte. If the bottom line is $5k and the client balks, it's all right there in front of him. "What would you like to cut out?" It's a choose your own price scenario.