Whether supporting vines or left bare, an obelisk provides an element of height to your garden. Make a contemporary obelisk by tapering two sides each of four posts at a 10° angle. Mark the 10° angles at the top of each of the four posts using a protractor and pencil, marking two adjacent sides of each leg. Then make two cuts on each leg to create an angle. Glue and screw the posts together to form a pyramid. Add supports and paint or stain.