Tips for reducing your portion sizes and the total amount you eat when dining out…
Ask for a "to go" box when your meal is served.  Immediately split your meal and take half of it home to eat for another meal the next day. Restaurant portions continue to increase in size. This tip will immediately cut your portion in half.
Stop unlimited refills of chips and tortillas at Mexican restaurants.  Ask for a specific amount to start with. For example, a small bowl of chips instead of a large basket. Just one tortilla instead of several. If dining with others who are not watching their weight, just ask for these items as individual servings for you. Then stop when yours are gone.
  Ditto for bread and rolls.  Ask for just one roll. Ask the waiter not to bring refills to the table.
Order from the children's menu.  You may want to call ahead and make sure adults can order children's meals. If they don't, ask if they'll do a special half size dinner. If they won't, then plan on splitting the meal and taking some home.

Order water and not a beverage with calories.  Then you can have all the calorie-free refills you'd like.