To make 5 of these 5"x5" boxes I used 1 yd of 9 oz canvas, 1 yd of quilter's cotton, and 1 yd of the stiffest interfacing I could find.
To begin I used my rotary cutter (oh man to I love that sucker) to cut the interfacing into 5"x5" squares. I cut the canvas into 6"x6" squares and the quilter's cotton into 6"x7" rectangles. You will need five of each per box. 5 of my lining pieces are 6x6 because I messed up when I was cutting, but if you pay attention the entire time you shouldn't have this problem.
Then I sewed the interfacing to the center of each canvas square. I made them smaller than the canvas because the interfacing was so stiff that I didn't want it in the seam allowances, but this does mean the stitching holding it on is visible from the right side. My fabric and thread are both black, so you really have to be looking closely to find it, but if you chose a printed canvas or your thread wasn't a perfect match these stitches will be visible.
Next I sewed four of the squares together in a line using 1/2" seam allowance. These are the sides of the box.
Then I sewed on the fifth square to make a sort of 'L' shape.
Now comes the slightly tricky part. Between the canvas and the interfacing you end up having to kind of manhandle the box to keep it under the pressure foot while you sew. Start sewing the sides of the box to the bottom (the small leg on the 'L')
When it is all sewn together turn your box right side out.
Now sew your lining pieces together the same way you did the box. They will be much easier because they are nice and limp. If you are using a patterned lining make sure you orient your pattern in the same direction for each side piece.
With the wrong sides out fold down the top edge 1/4" and sew. This will be easier if you have the kind of machine with a narrow arm, but it's not hard even without one.
When you are done with the hem put the lining into the boxes. Poke the lining down into the corners of the box.
Then fold the top down over the edge of the box and admire how cute it looks!
If you want to you could sew the lining to the box by pressing the top 1/4" but not sewing anything until the lining is in place, but I knew I would have make-up and lotion in at least some of these and I wanted to be able to throw the lining into the wash if need be.
One of my boxes is 1/2" shorter than the others because my lining was shorter, but I still wanted the cute folded down visible lining so I trimmed the top of the box down to be even with the interfacing before putting in the lining. If each box was next to each other I might be able to tell one was shorter and it might bug me, but with stuff in between each box on the shelves it's not obvious that one is smaller.
I've been using my boxes for a couple of weeks now and I totally love them. This is the most organized and the cutest I think my bathroom has ever been, and next week I can start sharing non-bathroom related home decor projects with you!