Should I have a polariser?

I am starting to get some portrait requests in (for free at the moment to use in my portfolio), and I have a shoot with a gorgeous fashion student/model for a session in July. The question is, do I need a polarising filter? Would it help with blown out skies, colours etc?

Who uses one for portrait/model shoots?

Cheers,
Tom

A polarized filter is nice to have but I don't use them for portraits. Are you shooting natural light or with your own lighting. Polarized filters work best with the sun at a 90 degree angle to your camera lens. With portrait shooting I'm changing my position all the time working on composition. You have to turn the polarized filter to get the best affect and this means you are adding just one more complication in your work stream. You'll have enough to worry about without dealing with a polarized filter.
That said, I do have one in camera bag. If you do purchase one, do not buy a cheap filter. It's one more piece of glass between your subject and your sensor. Would be a shame to muck up your 70-200 iq with a $25 dollar piece of glass! Best of luck!