First of all I cut the fabric in half which resulted in two equally sized squares - my measurements were restricted as he'd already bought the cushion pads to go inside and the only way they would fit was if I used all the fabric - not even a millimetre went to waste.
Next I folded over one edge of each square by 1mm and ironed along it to create a fold - I loathe ironing and avoid is as much as possible - sewing is the only time I pick one up. I never buy clothes that need an iron so it's lucky I don't have a normal office job as I couldn't handle having to have crease-free shirts.
Then I pinned the zip along the inside edges - if you position the pins like this you can stitch directly over them.
I stitched one side using a straight stitch on my sewing machine...
And then the other...
Finally I unzipped it, stitched the front and back squares together, neatened the inside edges then turned it through.
And here are the pair in situ in his flat.
If you fancy an equally attractive cushion in your own home, I've also found some other 'hunk' cotton variations:
Workmen fabric from FabricInspirations.
Firemen fabric from J and O fabrics (who also sell the cowboy print).
Hmm, now then, what to make for myself...