Keeping this in consideration, how do you prevent wood from tearing?
Tear out marks will ruin the look of your project, but can prevent them with a simple trick. First, make sure to always cut plywood with the best side facing down, so the blade won't mark it cutting up through the wood. Tear out occurs when the blade exits the top side of the wood and catches the veneer.
Likewise, what is tear out in woodworking? A “Type I” cut occurs when the wood fails ahead of the tool's cutting edge. If the tool is cutting against the grain of the board, then the cut goes deeper than intended when the shaving is levered upwards by the tool. Because the failure occurs below the line the cutter is traveling on, you get tear-out.
Just so, how do you cut wood without splintering?
To eliminate the splintering, first apply a strip of 2-inch-wide masking tape across the door. Clamp a framing square or other metal straightedge along the cut line. Then, slice through the tape and into the door using a utility knife. You should make several firm passes.
How do you make end grain look good?
Simply sand the end and edge grains to one higher grit than the side grain. So if you sand the side grain to 150, sand the end grain to 220; if the side is 220, the end and edge grains should be 320 and so forth.