Dieting is difficult, and keeping the weight off can be equally as challenging. We have all heard the reports that diets don't work, which a reason I like to think of the whole ordeal as a lifesyle change and not a diet.
To maintain your ideal weight, I strongly suggest picking a red flag weight. Pick a weight and vow to never get heavier than it again. It is normal for your body to fluctuate five pounds - especially for women, so I recommend picking a weight that is ten pounds heavier than what you “normally” weigh. If you hit that weight it is time to reevaluate how and what you have been eating, as well as review your exercise plan and if you are sticking to it.
If you don't like to weigh yourself, pick a pair of pants as your measuring stick like your favorite jeans. If they start to feel too tight it is time to reevaluate your situation. This sounds a lot like The Jeans Diet that Eva Mendes uses to maintain her ideal weight.