Open a new document in Illustrator. This tutorial uses US Letter size with landscape orientation, but you can use any size of paper as long as it fits your printer. You will have to adjust the sizes of the individual parts of the box to fit your paper size. This box measures 6" X 3.5" but you can adjust the sizes to make a custom size box.
Turn on the rulers (cmd/ctrl + R or View > Rulers). Right click a ruler and choose inches for the unit of measurement. Type D to set your colors to the default white fill and black stroke.
Select the Rectangle tool (M) in the toolbox and click once on the artboard to open the rectangle options. Enter 6 in for width and 3.5 in for height to make a 6" X 3.5" rectangle and click OK. Switch to the Selection tool (V) and drag the rectangle to the top of the page so you will have room to add the one for the back of the box.

