I used to get really PO'd and yell at drivers all the time. I found that it really doesn't do any good to yell at people after the fact. Once they've cut you off, yelling isn't going to do anything except possibly incite them to come back after you (which happened to me a couple times.)
I've found that pre-emptive pointing and warning works much better. Don't assume that eye contact means that they're actually paying attention. When approaching a driveway where a car is waiting, I point at the driver and shake my head in the universal "no" signal. If the window is open, I'll accompany this with a quick shout of "Do NOT!" I haven't had anyone pull out in front of me for a long time.