Here are a few tips that I use when buying new:
1) If you are ordering new, American Express has a car buying service. You build the truck of your dreams, then they give you a pre-negotiated price that is usually $2K under invoice. They provide a list of dealer in their program in your area. Some may say no as it's dealer optional, but I had one dealer that was willing to order one to my specs and price. At the time I bought, I did not go this route as they had stop building 2014's. But a good way to go with the 2017's.
2) Know the invoice price. Edmunds.com can help with this along with the price others are paying. With all new cars/trucks, there is something called the "hold-back", which is the profit a dealer makes if he sells at invoice. This can be negotiated with slow selling vehicles.
3) If buying off the lot, get the VIN and check all the options to select when using Edmunds.com to calculate invoice.
4) Find a credit union and ask their new vehicle interest rates. These will usually be very low compared to what the dealer offers. In my case, I found a local credit union that had a 2.1% rate.
5) Use ford's site to identify which dealers have the truck and options you want.
6) Don't trade anything in unless you need to for tax reasons.
7) Just laugh at anything the dealer adds to MSRP (e.g. prep fees, pin striping), and say you are not paying for those items. Some items may be worthwhile however.
8) Be prepared to walk away and go to another dealer.
In my case, there were only 3 Special Edition 2014's left in Florida. One dealer was 100 miles away, so I drove there and negotiated $500 under MSRP. I could have done better, but he had the exact one I wanted. Then came the interest rate, which he quoted at 6%. At this point I said I could get a better rate in a couple days at my credit union and started to walk out. The manager came back with 2.5%, and the deal was done.
The next day there were no more 2014 SE Raptors in Florida. I was happy!