As long as doors have existed, people have employed doorstops to hold them open. Although doorstops have evolved over time from a rock or brick to something as ornate as a decorative statuette, the simple wooden door wedge is still the most common. Make door wedges for every door in your house from one 2-by-4 inch stud in less than an hour.
Secure a 2-by-4 stud to your workbench with a clamp so that it overhangs the bench at one end. Line up a protractor with the edge of the wood. Mark a 20-degree angle on the stud with a pencil until it contact the opposite edge. Make a diagonal cut through the wood along the line with your saw.
Sand down all sides of the wedge with medium grit sandpaper. Concentrate especially on the cut side to prevent rough edges that could mark the floor or splinter off into someone's foot.
If you want your project to have a more finished look, finish the wood with a brush-on polyurethane sealer or wood stain. Allow one side to dry sufficiently before staining the other side.
Move the clamp further down the stud. Saw a perpendicular cut at the edge of the first angled cut to create another door wedge. Line the protractor up against the stud and measure a 20-degree angle for the next set of door wedges. Repeat the process, measuring and cutting until you have as many wedges as you need. Sand and then stain if desired.