I found that focussing on my breathing while they're drawing the blood very helpful. In and out 4 counts each. Look away and visualize a beach or something.
BTW - it's an aquired thing. I used to pass out practically, and when I was hospitalized with complications with Quinlan's pregnancy, they drew blood like every other day. After a while, it was like "here's my arm." or "which one do you want this time?". I had little needle tracks running along my veins on the insides of my elbows.
-------------------- Formerly HanSolo. IBS, OCD, Bipolar, PTSD times 3.