I have published this post in the past, and decided it was worth “updating” and publishing again!

1.  Purchase an ottoman from a discount store or Thrift store, or make one out of plywood.  The plywood box I made measures 20” wide x 16” tall, finished.  I used ¾” shop grade, good one side, maple plywood. 

2.  If you are using a plywood box, first wrap it in batting to give it some softness.  I sprayed adhesive onto my box, one side at a time, wrapped all 4 sides and then the top.  I made the side pieces long enough to wrap under the box, so it wouldn’t scratch my floors when I move it.  You could also attach small round feet to each bottom corner.
3.  Make the cover.  I used 55% hemp/45%cotton corduroy, but any sturdy fabric will do.   I make my covers ½” bigger all around than the box, so it will slide on easily. I use 1/2″seam allowances. For this box that measures 20″ x 20″ x 16″ high, I cut out 4 pieces of fabric 17 1/2″ x 18 1/2″ (2″ hem) and 1 piece 17 1/2″ square for the top.  Sew your 4 side pieces together, finish the edges, then attach the top piece, making sure all the seams fall exactly at the corners.  I like to “round” my corners a little, so the slipcover will lie smoothly on the top. Try the slipcover on the ottoman or box, pin the hem, press and stitch and you’re done!

4.  Optional:  Make a cushion to match your ottoman.  Using 4” foam, wrapped in batting, I made a cushion with a removeable cover to sit on top of the ottoman.  This way the cushion can also be used elsewhere when you need extra floor seating!  You could also have a piece of glass cut to size and place it on top of the box to make a perfect night table or end table.  Or make 2 ottomans and place them side by side at the end of your bed, or in an entrance as a bench.
Custom cube slipcovers
Custom box cushions
Add some bolster pillows for a finished look.
 
Slipcovers I made for a client – fabric from fabric.com