To begin building our plastic bag saver, we'll cut the pieces to length. Start by square-cutting two pieces of 1x6 to 32" in length with your Compound Miter Saw or Circular Saw. These will be the two sides of the box. Set them aside for the moment.
Second, square-cut two pieces of 1x6 to 9-3/4" in length. These will form the two parts of the top. Set these aside as well.
Third, square-cut a piece of 1x8 to 9-3/4" for the bottom of the unit, and another piece of 1x8 to 32" for the back.
Next, adjust the bevel on your miter saw or circular saw to 15-degrees, and square cut one end of the remaining piece of 1x8. Do not remove any more than one-inch of stock in cutting the bevel. This piece will become the front of the bag saver.
Finally, return the saw's bevel to zero-degrees and, if you're using a miter saw, set your miter to 15-degrees. Retrieve the two side pieces you cut at the beginning of this step. On one end, make a mark two-inches in from one side and scribe a 15-degree line from the mark to the opposite side of the board (as shown on page 4 of the free
woodworking plans you downloaded in step 1). Repeat the mark with the other board, and then cut the partial miter on each of the two side boards.