How can I make it easier for a nurse to place an IV?

I have horrible veins for no particular reason. I am 20 years old, rather healthy, I never did drugs, I am not overweight, with good low blood pressure, and I have a high pain tolerance so I am not "squirmy."

Almost every time I have to have an IV placed, it takes the nurses forever. Five years ago I was in a horse accident and broke a few bones, and they couldn't get an IV in to give me pain meds until after I was ambulanced in, I went for about an hour without an IV. Three years ago I had a two neck surgeries where they ended up putting a central line in, because they couldn't start a regular IV. Last December I needed to get surgery to remove some hardware, and it took 7 nurses and 45 minutes to get a line in. This summer I was hospitalized for Serotonin Syndrome, and because I was on a heart monitor I needed to be on an IV. It took 3 nurses to get the first one in, it went bad after a day, and then they tried to get another one in for an hour and a half, before just giving up. I am REALLY hard for nurses to stick. They try everywhere, up to my elbows, on the backs of my hands, in my wrists (that one hurts most), and even on my feet.

Tomorrow I am getting a small procedure done on my neck, and I will need to have an IV. I am going to hydrate as much as I can before I have to stop having liquids, I am going to take a muscle relaxant and just hope for the best. I called the surgery center before hand to let them know how bad my veins are, and they didn't really seam to believe me. I hate going through so many sticks, and I hate the bruises that run up and down my arms afterwards.

I want to know what I can do to help the nurses out...what will make my veins easier for them to do?