This is a fun project that's easy enough for the kids to do, and it can be as elegant or as simple as you like. All you need is a small jar, such as a baby food or small jelly jar with a lid, and some cotton.
That's all there is to it! Of course, you'll probably want to decorate your jar with paint or decoupage. Butterflies locate their food sources by sight, so the more your feeder looks like a plant or flower, the better your chances of attracting butterflies. It may also help to cut out some fabric or plastic 'petals' and fasten them to the lid of your feeder.
To make butterfly food, simply dissolve one part sugar in nine parts of water. No coloring or other additive is needed.
Another fun project is to make a gardener's toolbox from a standard mailbox. Decorate the mailbox any way you like, and fasten it to a fencepost near the garden. A mailbox is the perfect size for a spare pair of gloves and a few hand tool. This is a great rainy day project for the kids, and it makes a terrific personalized gift.