The trick is to make it fun while also nutritious. Are there any dietary restrictions/allergies?
You also want small containers that they can manage, and consider a sectioned plate if the kids are fussy about "ewww, that yogurt touched my strawberry"! So...
- yogurt: kids tend to waste, so see if the family has (or will buy) those very small tupperware-type containers. I like the Rubbermaid ones with the red lids because the containers are square and easy for little hands to hold. Spoon yogurt out from the large, economical container into the small ones.
- cut up veggies like carrots, cucumber disks or spears (sometimes you have to take out the seeds but don't if they don't complain), thin celery sticks (no strings), green/red/yellow pepper strips, snow peas (de-string them and maybe cut in half), grape tomatoes (cut in half if the kids are choking age),
-hummus - great for dipping the above veggies or small crackers. Again, put in a small container or a sectioned plate so it doesn't slide all over
-PB&J - make one sandwich on whole grain bread, cut in quarters, give each kid 2 quarters. If anything goes uneaten, save for snack.
-turkey and cheese sandwiches, same as above.
- cheese cubes, string cheese, or slices
- triscuit crackers (no added stuff) - those are good for the dipping or the cheese slices
- mini pepperoni or turkey pepperoni slices. If you want to be clever, stack one on a triscuit and add a small slice of mozzarella cheese
-apple slices to dip in peanut butter or cashew or almond butter.
- fruit cubes or kabobs (unless they are too little to manage the toothpick, then just put a few pieces on the plate): watermelon, other melon, half a strawberry, a blueberry, a raspberry, half a grape (grapes are choking hazards), sections of clementine/mandarins (cut in half if needed). Go easy on bananas because they get brown if not eaten. Raisins and raisins are okay if the kids chew them.
- nuts - almonds or walnuts
- real mac and cheese (not the boxed stuff with powdered cheese - if you want a recipe, let me know). Make beforehand and heat up a small amount in the microwave.
- pancakes or French toast. I kick up the nutrition by adding soy protein, wheat germ and flax seed to the pancake batter (plus 1 fruit or a few chocolate chips - and this is a good place to use up brown banana slices!), or soy protein and flax meal (which is ground up flax seeds) and cinnamon to the egg batter. You can let the kids help you mix the batter, which gets them involved in cooking. I make a batch and then freeze/refrigerate the leftovers with a piece of wax paper in between the layers, and they keep for a few days in the fridge. I use real maple syrup and not the corn syrup that's just maple flavored; it's expensive but you don't let them drench the plate in it. You can add a squirt of Redi-Whip and a piece of fruit (berry, banana, let them choose) to it. You can make a face on the pancake with whipped cream and fruit pieces.
-tortilla wrap sandwiches: put some turkey and some shredded lettuce and some cheese drips or shreds on a small tortilla and roll up. You can use mustard or hummus as a spread instead of mayo.
- scrambled eggs. Let the kids watch (or help) you break the eggs and then break the yolks through scrambling.
- get popsicle makers and use fruit and water or some watered-down juice for them. Get the popsicle molds that have a straw and a little reservoir for catching/slurping the melted juice. Much less mess! Again, they can help you make them on one day for eating on the next.
It's okay to foster good habits, so that means letting them use a fork (try dessert/salad forks, as they are smaller) or kiddie utensils if the family has them. Put out a napkin and show them how to use it.
I would put only 4 things on a plate. Otherwise it's too confusing, and you want to mix it up from day to day.
Avoid juice - the new guidelines from the American Academy of Pediatrics says the sugar is terrible for them. Go to real fruits for the fiber and nutrition, and milk (if okay by the family) or water for hydration.