Cut a piece of cardstock 8 x 7 1/2. Score 3/4 of an inch in from either end on the 7 1/2 inch side. Now working on the 8 inch side we're going to make 4 score lines - 1) score 3/4 of an inch from one end, 2) 3 inches over from the first score line, 3) 3/4 of an inch over from the second score, 4) another 3 inches from the last score line. That should leave you with panels that measure 3/4 inch, 3 inch , 3/4 inch , 3 inch and 1/2 inch.
Now cut the scor lines on the 7 1/2 inch ends as indicated in the photo above. Then to assemble the box, add redline tape (or the adhesive of choice) to the bottom side of 3/4 inch tabs. Note in the photo my redline tape is facing my scorpal. The 3/4 inch tabs are folded up and in and the 3 inch ends are then folded up