Pick one to three of your favorite dishes to highlight on your menu cover. These should be professional photographs that show every detail of the dish. The food needs to be taken in natural light (see "References" for more information). You may also want to create a separate menu for lunch and dinner dishes, with different pictures on each version.
Another choice for your menu cover is a simple solid background with a large copy of your logo placed in the center. This will draw attention to your restaurant name and help promote your brand.
If you want to really get your restaurant customers in the mood to eat when they look at your menu, place pictures of people eating the food on the front cover. These should not be random shots from a royalty-free catalog---they should be actual people eating your food. Use close up shots of the food on the fork going to the diner's mouth and photos of people sitting at your booths eating.
To draw attention to your amazing restaurant staff, take a group shot of your employees smiling for your menu cover. You can either simply place a large photo, along with a small logo, on the cover, or add a smaller photo of your staff at the corner or bottom of the menu with other main elements (like photos of food dishes and your motto). Have one or more employees hold out a plate of your most popular dish in the photo.
If you serve ethnic food that can be attributed to one specific area or region, place a nostalgic picture of people from that ethnic group eating on your menu cover. For instance, if you serve authentic Italian food, add an old black-and-white photo of an Italian family eating around the dinner table. This will add a special charm to your menu that is hard to forget. Also include your logo, motto and a photo of one of your most desired meals on the cover along with the old photo.