For either chicken or steak:
You'll need large onion, a couple of bell peppers (preferably red, yellow or orange), a couple of tomatoes.
Cut your meat (preferably partially frozen - easier to handle) in about 1"-1.5" cubes.
Cut the veggies in squares that are approximately the same size. I.e. for the tomatoes, use only "the walls".
Start by skewering 1 onion slice, 1 pepper, 1 tomato and add the meat. Keep doing that until the skewer is 80% full.
After all the skewers are populated, season and marinate them for at least 1/2 an hour.
Use the marinade to brush the skewers while cooking (preferably over coal/wood)
These are a lot of fun for kids to make. They love to participate.
Obviously, you can use any veggies you'd like such as mushrooms, zucchini, artichokes, potatoes, etc.
Have fun!
PS Lamb is also awesome with these...