I think key is to be patient, shop around, be willing to walk away AND if the price is close/truck is right also be willing to jump & make a deal a quick too.
We walked in at 7pm the night before the 4th of July holiday to buy our last vehicle. We had eaten already, and had someone watching our little girl. We could have stayed there all night- and they all just wanted to go home. But you know car dealers and salesmen, they can't let a sale go. I took my sweet time to look over any offer they put in front of us, re-calculated all of their numbers on my own, and kept telling them they were getting close. At some point they just said **** it, give it to him for the price he wants so we can ****.
The finance guy banged out the 0% loan in 5 minutes and didn't even try to upsell us all the shit. It worked out great.