Here's a fast, foolproof way to make perfectly square, 90-degree crosscuts with a circular saw. Mark the cut line on the board and position the saw with its blade on the line. Hold a framing square with its long, wide blade against the edge of the board and its shorter, narrow tongue against the shoe plate on the saw. Then squeeze the trigger and guide the saw along the framing square to produce a straight, square cut. This technique makes crosscuts up to 14 inches. For crosscuts up to 22 1/2 inches, flip the square around and place its long blade against the saw shoe.