The instructions below are for an 18x24x6-inch cushion, but you can adjust the measurements for custom window seat cushions or bench seat cushions.

What You’ll Need:

1 yard of decorator fabric (52/54-inches wide)1-1/4 yards of fleece1-1/4 yards of extra-loft batting1 17x23x5-inch piece of high-density foamUpholstery or carpet threadHeavy-duty spray adhesiveHand-sewing needle and buttons

Quantities specified are for 52/54-inch-wide decorator fabrics. All measurements include 1/2" seam allowances unless otherwise noted. Sew with right sides together unless otherwise stated.

Step 1: Cut the Materials

To make the best use of your fabrics, cut the pieces in the order that follows.

Step 2: Prepare the Foam and Fabric

Use heavy-duty spray adhesive to glue the extra-loft batting to the corresponding sides of each high-density foam piece. Line each decorator fabric piece with corresponding fleece piece; baste each pair together.

Step 3: Assemble the Cushion

Sew the fleece-lined gusset rectangle to the cushion top rectangle; clip the corners as necessary and turn under the raw ends. Repeat by sewing the opposite edge of the gusset rectangle to the cushion bottom rectangle. Leave a large opening; turn to the right side. Insert the batting-covered foam shape into the cushion cover. Hand-sew the opening closed.

Step 4: Finish the Corners

Give each corner of your box-edge cushion a little extra polish by adding a seam. Along each side seam, flatten the edge by pushing the batting-covered foam shape away from the seam; pin, like you are making a hem. Using a long running stitch and upholstery or carpet thread, tuft the edge through both adjacent sides.

Step 5: Tuft the Cushion

Using a fabric pen, make matching marks for the placement of four buttons on both sides of the cushion. Using upholstery thread and a needle, hand-sew the buttons onto the cushion. Now that you’ve learned how to make your own cushions, give these upholstery projects a go.