I would just add a couple of points, because everyone else has pointed out some great ideas already.
1. Take a "Before" picture. I wish I had (thanks to Facebook I will still have all the before pictures I could want
6 months from now when it seems like you aren't making progress, or not making progress fast enough, take a look at what you USED to look like, and realize how far you have come. We all know what a picture is worth.
2. Get in the right mindset at the beginning. If you start F2S with the idea "Well, I'll try it and see if it works", you are already allowing for failure.
Look at the stories here - we all know it works. The question is, are you going to quit before you see the results you want? There is no disputing that this way of eating will take the pounds off for virtually everyone; some just quit before the magic starts. And don't decide to do this because you have an upcoming class reunion, a wedding, or any other one-off event; that's a temporary thing, and your results will also be temporary. Do this because you want to see your kids grow up. Do this because you want to see your grandchildren grow up. Do this so your spouse doesn't spend his or her golden years alone. Only you can decide what your real incentive is, but make it a good one. Then leave no options for failure! As your clothes become too big, throw them out or donate them. Tell others of your plan. Ask someone to hold you accountable.
I guess that's it for now.