Mix an array of different greens. Beans add fiber. Load up on garbanzos, black beans, kidney beans, lentils, etc. Use dressing in moderation, and avoid creamy dressings. Make your own vinaigrette, going light on the oil.
Croutons can be high in fat.
To make your own low-fat croutons, cube slices of bread, season with herbs and just a touch of olive oil, and then toast. Turn a simple salad into an entree. Try topping green salads with leftover steak, chicken or tuna. Chicken and turkey provide lean protein. Fish also is a good source of a good fat, omega-3s.