Simple saw guide to quickly make square cuts with a hand saw.
Step 1: Wood
Cut two pieces of wood to form the handle and guide.
Step 2: Glue
Glue and clamp the pieces at a perfect 90 degree angle.
Step 3: Screw
Reinforce with screws.
Step 4: Magnets
Drill holes and epoxy magnets in place along the saw guide edge.
Step 5: Test
Make a cut with the jig and test for square.