1: Place mat facedown on work surface and center wall cube on it, face down. Use a pencil to trace the inside edge of cube on the mat. Cut mat to size with the ruler and box cutter, cutting along the outside of the penciled line so the mat will fit snugly into the cube.
2: If you want a background other than your wall, trace the opening of the cube on the cardboard and cut to size. Repeat with colored paper or fabric.
3: Use glue stick to attach paper or fabric to cardboard. Press covered cardboard into back of the cube, taping in place if necessary.
4: Determine wall location; using a level to ensure accuracy, prepare wall with nails or screws according to wall-cube hardware instructions.
5: Fit mat in cube so it is inset about ½ in. from front. If mat is a loose fit, gently reach into mat opening to tape to inside of frame.
6: Hang cube. Gently place saucer and frog in cube.
7: Use turkey baster to slowly fill two-thirds of saucer with water; position cuttings in frog through mat window.