1. Internet: Does the restaurant you are going to have a web page? Check it out before you go in the privacy of your home. Scope out the menu, and make 2 or 3 strong CE choices so when the moment of truth comes, you won't be tempted to blurt out "Can I have fries with that??" You'll also have a prime choice, and then a backup choice if the restaurant is out of that dish.
2. Eat Ahead of Time: No brainer, and the oldest trick in the book. Before you go to the restaurant, have a yogurt, some fruit - anything clean to take the edge off your hunger.
3. Salad: Order a salad for the appetizer course - people who eat salad first generally eat about 20% less food overall during the course of the meal. Ask for "no croutons or cheese" and feel free to ask for extra tomatoes or cucumbers ( etc ) if that is your wish. Pick the balsamic vinegar salad dressing - 99% of the time, it will be the cleanest option on the menu.
4. Double Up: If the meal of your choice ( some sort of clean seafood, etc ) is supposed to come with a big honkin portion of cheesy rice or something definitely not CE ( fries, au gratin potatoes ), ask the waiter if you can get a double portion of veggies instead of the portion of non CE food. Most places are happy to handle such an easy request.
5. Eat Some, Take Some: Most restaurant portions are enormous - enough for most people to have at least 2 full meals. Immediately upon receiving your meal, segregate a portion of your plate to "take home." If you really want that portion after eating the other half - go for it. But, if you are nearing full - stop, ask the waiter to take it away, and bag it for a doggie bag!
Some CE menu words: steamed, roasted, grilled, poached, broiled, au jus or in its own juice ( but be careful, that can indicate added salt ), garden fresh, baked in tomato sauce, mustard, vinegar, and/or marinated.
Leave these words for folks who want to remain overweight: fried, deep fried, french fried, buttered, sauteed, escalloped / scalloped ( means with cheese ), cheese sauce, creamed, Alfredo, au gratin ( more cheese ), braised, pan roasted, crispy, in gravy / in hollandaise
( Thanks to Oxygen magazine for that list of words! )