Coloring is one of the easiest and most creative crafts appropriate for preschoolers. There are crayons and markers available that are safe, non-toxic, easily washable and in nearly every color imaginable. Set a goal such as having them color their favorite person, their family or an animal. You could also give them coloring book worksheets to teach them how to color within parameters and lines.
Painting is another simple activity that opens up a lot of imagination. Watercolor paints are easily cleaned and non-toxic acrylic paints are another option. Have kids paint on paper or canvases, or let them paint small pieces of clay pottery, picture frames, name tags or other objects. Paints can be slightly messier than crayons and markers, so ensure you lay out newspapers in the art area to make for an easy cleanup.
Play dough and clay can provide a fun art activity and allow preschoolers to mold and shape whatever they like, then reuse the clay to continue molding other pieces. Kids can also play with modeling clay to mold pieces to dry and allow kids to take home. For modeling clay, let preschoolers paint their dried pieces with acrylics to add some color. Another craft with modeling clay is having kids make hand or footprints in clay then give the impressions to parents as keepsakes.
Food art makes for yummy activities in which preschoolers can play with their food. Add food dyes to bowls of vanilla pudding to make edible finger paints. Paint dried pastas different colors by shaking up pastas in plastic bags filled with paint and letting them dry, then having kids glue the pieces to sheets of paper in various designs. Another idea is to provide baked goods such as cakes or gingerbread cookies and let preschoolers decorate them with frosting, sprinkles and other pastry decor.