For a quick one, you could even let your strips vary from 4" to say 6". If you cut your backing, then place your batting on top and start with your strip in the center, you could probably lmachine quilt at same time--flip and sew method and skip the borders in favor of a binding. As long as they're colorful and soft, kids will love. I'll bet there's a better way I could have said that! Your six inch strip might be a fun focus fabric, animals or birds, teddy bears or whatever!