Step 5: Drill peg holes for shelf supports
Next, for the interior of the cabinet storage area we'll add the peg holes so that you can insert the shelf and different heights according to your current and future needs. First, mark a vertical line about 3" inside the front and back on each side. Measure out how far apart (height) you'd like the holes from each other. I chose to have it adjustable at a 2" intervals, which gave me 3 different heights for the shelf. Just take the 3/16 drill bit and bore out a 1/2" into each mark you made for each individual hole. A drill press would be ideal here if you have it, otherwise, just be careful you don't go too far.