I have a patio table and chairs that are great, but not particularly fashionable. I looked at new cushions, but most of them start at over $30 each. So, I thought perhaps a slipcover would be a good solution. I started at Home Fabrics and found several good choices of fabrics that I liked. I love green and brown, so this harlequin pattern was perfect (and at less than $2 a yard, it made the decision easy). I toyed with making the slipcovers more fancy, adding ties etc..., but in the end went with simple instead.
I laid out the cushion and measured around giving myself a 2" allowance around each side. I used the fold to help make things go faster. Turns out I needed 1 yard per cushion since I had 54" wide fabric.
I used the iron to fold and press along the open edge, then pinned the slipcover inside out. I sewed along the top and bottom as well as part of the long side (but I left a very long opening to slide the cushion in). Be sure to really back-stitch the edges of the cushion opening really well so that the seam doesn't tear out while you are stuffing the cushion in.
Sew the opening shut (or use some stick-on velcro or snaps).