Portion size -- it doesn't matter how "good for you" the food is -- if you eat too much of it, it's not. If you are eating at sit down restaurants, order salad while others order an appetizer and then order an appetizer as your main meal. Also ask if they will plate an entree in an appetizer portion. I did that at WDW and most restaurants were happy to do so.
Bank points each day for one treat and decide on the point range of the treat ahead of time. That way you won't feel guilty. Nothing tastes good when you feel guilty about eating it.
Eat 4-6 small, low point "meals" instead of 2-3 big ones. That way you can stay within your range but not feel deprived if you happen to be traveling with grazers who snack all day.
Save your points for something you can't get somewhere else. For example, popcorn. You can get popcorn any day of the week. Splurge on a Dole Whip or giant turkey leg instead.
Look for carrots, grapes and other healthy alternatives. They have them at WDW so they may also have them at DL/CA.
And drink that water!
Have a great time.