Quote from equestriRN
1. Don't forget to drop your angle and advance the needle 1/4" after you get flash. The actual cannula that you are threading is shorter than the needle tip - you need to get that inside the vein too! If it won't thread, you are probably butting it up against the outside of the vein../
I know they teach you in school to go in at 45 degrees or something ridiculous like that, then drop your angle. I swear this causes more punctured veins than anything! I prefer to start out with as small an angle as possible, not precisely flush with the skin but pretty close.
Also, when you get flash back, pause and don't get excited. Advance just a teeny bit more, then advance the cath slowly. Doing this step quickly or too hastily can be the downfall of many an IV start.
And my two biggest pieces of IV wisdom:
1) Have some one show you the tricks and specifics of whichever IV product you are using at your workplace. We switched from Insyte to Nexiva and there was a big difference in technique between the two.
2) Try using a manual BP cuff (inflated to around 90mmHg) instead of a tourniquet. I always use the BP cuff, both for comfort of the patient, and the fact that I've seen a dramatic decrease in veins blowing since I started doing that, oh, five years or so ago.