Yes, practicing helps! Following various IV nurses, can help too. Each one can give you tips and pointers. A course is great idea, too.
Some things i do, to start IVs on hard to get patients, include,
if vein is just invisible, sometimes it helps to wrap arm in warm warm wet towels, and surround that with a "chuck" (plastic bed liner thingie) and give it about 5 to 10 minutes. Sometimes makes previously unseen veins bulge up easier to see or feel.
Have patient open and close fist, over and over, if that is possible.
another thing that drives me batty, is seeing anyone slapping around on a patients arm to raise their veins. It can redden the skin, and worse, it is unnecessary useless pain, and it hurts and it makes the patients tense. don't do it.
I rub rub rub the vein i am about to stick, in downward manner,
for quite a while prior to sticking it. This helps fill the vein, and also increases my chances of spotting any knots, curves, hardened valves, etc, so i can avoid those spots.
Rub it, don't slap it.
Also, be aware, the smaller the bore of needle you are using, the slower the flashback will be. Your chance of going through the vein, is higher, cuz your flashback is so slow in tinier needles.
Of course, have everything ready to hook up once you are in vein, and i almost always place either a chuck or a towel under my site. Murphy's rule, if i don't, that vein will gush while i am hooking up the IV line, and stain the sheet...
TALK to the patient, the whole time. I do, anyway. I get the patient talking, about whatever, while i insert the IVs. It helps distract them. Mostly, all you have to do, is ask the occasional question, or give feedback, seem interested, "Wow, that musta been something! When did you finally find your dog again, then?" or whatever.
Whatever they are interested in, i get them to talk about that. Reduces the tension surrounding the IV insertion, for both of you, if you can engage pt in conversation. I've had so so many ppl state, "wow, that didn't even hurt!" and i think,
it's cuz they've been busy reliving when their last vacation or whatever, the whole time/not thinking about what is going on.
Re: getting written up negatively by the patient, if you do miss--
The patient will be more likely to "like" you, even you miss, if he felt you were interested in HIM, as a person. Most ppl do like to talk about themselves, ha ha!
silently sticking needles into people, makes it hurt more, imo.