A sprinter will always be able to do well in a sprint. Only in the difficult races will a sprinter be neutralized (hills, wind, small group, etc). A good sprinter will get within range of the front, go when it's best, and hope that their sprint lasts long enough to get to the line.
I don't look for a wheel unless, as you said, I have a teammate leading me out. I look for an area. I look for patterns. I look for holes. Sunday I was on the yellow line going into the sprint (road curves right then left). I was so far back I thought I had to go the far way around (hence yellow line in a long right curve). Then the whole front of the field started crossing over (full road at that point). I looked right, there was a huge hole, I swung right like I was diving into a right turn, got to the curb, and launched up the right side. I rocketed past everyone in the field, and won the field sprint. I passed a few break guys on the way (they realistically started the sprint 30+ meters clear) so I managed to get 7th.
It helps to find a good sprinter to follow but that's assuming you can then pass said sprinter in the sprint. So for example if you got on Cavendish's wheel, that's great, but when he goes now what will you do? I've gotten on superior sprinter's wheels, launched when they launched, and watched them ride away from me. That's what life is like for a non-sprinter, and for me much of the time.
It's best to find those guys that are strong but don't have the race ending sprint. They usually try and get top 6 or so, and they'll go early or whatever to try and get a good place. They know they'll get beat but they'll try it anyway. I don't look for them but often they'll lead out a bit early and if I am there I'll follow.
Ultimately though if you don't have a massive sprint then forget it. Field sprints aren't where it'll be at.
I have a post somewhere in here about how you know if you're a sprinter. A few thoughts come to mind, but the main idea is you constantly think you sprinted when you weren't supposed to sprint because no one else is going fast. So you think you jumped on the wrong lap since everyone shot backwards when you jumped. Or you thought that the group ride wasn't sprinting at the normal spot because when you went everyone else shot backwards. Or you start making stupid long sprints because it doesn't seem fair if you jump at 200m to go, so you go at 300m or 400m or you wait until 75m and try and pass the guys up front in just a few seconds.
In all those situations everyone else is sprinting. You just don't think so because they can't go nearly as fast as you can.
That's when you're a sprinter. If you never thought that then you will need to figure out how to wear down the sprinters.