It's easy to get all hyped up into any program, see results and let them dwindle and then reminisce on how "I used to be able to do this or that".
Thing I do to keep myself in check.
1.) Update and continually check my short and long term training goals
2.) Keep the zone in check (a watch with 3 alarms/day will remind you of those pesky snacks that are easily forgotten)
3.) Have an upcoming competition that everyone you know knows about ! (people that have no idea what fitness is will tell you when you eat bad food, haven't worked out etc) or they may just nicely ask how training is going. a great reminder.
4.) compare myself to EQUAL athletes. through the online crossfit community and blogs its fairly easy to find an "online training partner"... or better yet a real life one... even if you can't train together all the time, a re-union will remind you that you are doing well or falling behind.
5.) re-educate: further crossfit reading, zone books, specialist books, and new training gear will always re-motivate to use and try new and old things.
6.) watch the crossfit video of the day before a workout, or just as a reminder that there are girls that whip me...(this keeps me up at night..j/k)
7.) access whole life (hours awake during day, sleep, food, stress etc... ) 7P's from Bravo 2 Zero "Proper Planning and Preparation Prevents Piss Poor Performance"
8.) Record results from workouts and compare myself to my hardest competition (myself)
This is just a random smattering of things.. feel free to add your own tips/tricks to comments....