Position the pieces to be joined as they will be when the joint is complete and use a pencil to mark both pieces to make them simple to realign. Mark the inside faces of the two pieces where the dowels will align them correctly. Bore a hole in each piece, the size of your dowel. Use wood glue to fasten the dowel securely, cut it to length to fit the holes and insert it into one side, realigning the second piece so that the hole fits over the dowel to complete the joint.
Larger dowels, 1/2 inch thick or bigger, can be used for a variety of pegs and hanging hooks. Simply bore a hole the size of the dowel into the mounting surface at an angle. Cut your dowel's end at the same angle and sand it smooth. Glue the peg and insert it into the hole, tapping it home with a hammer as needed. Add as many pegs as needed. Anchor the mounting board to the wall studs for a strong coat or hat rack.
Use a 1 1/2-inch dowel to create extra hanging space between any two walls that are less than 4 feet apart. Use a stud locator to find the supports in the walls and mount closet bar cup brackets at either end using a drill and one 3-inch drywall screw through each cup. Cut your dowel one-eighth shorter than the distance between the inside faces of the two cups and insert it from the top to complete the project.
Cut a piece of 3/4-inch thick dowel 14 inches long to create a paper towel holder. Cut a circle from 3/4-inch thick plywood a little larger around than a roll of paper towels using a jigsaw. Trace the circle on paper and cut it out. Fold the paper in half both ways to locate the center. Use the paper as a template to find the center of the plywood circle and drive a single 3-inch screw through it into one end of the dowel to finish the holder.