This is not strictly so much a pattern as a set of conscise guidlines for creating a Rectangular/Square shaped cozy for any object. The one shown here is for a DS Lite.

Main construction is a rectangle of trinity stitch that creates the case body. Edging is then added and the item is steamed to create a pocket.
Optional instructions for lining and creating the straps are included.

At a later date I will include instruction on how to make the copper wire eye and hook catch.

Time to complete project
This project took me a day and half from start to finish. This includes crocheting the cover and straps and lining the case. I am a exceptionally slow crafter and I was designing as I went along… so I expect that most people could get this done in a evening or two.

Yarns used
Case:Twisted Fiber Arts: Kablam in Ravelry colourway (Merino, Nylon & Bamboo). Fingering weight aprox 133 tp 200yds used.
Straps (Optional): Sirdar, Snuggly DK in Black (Nylon & Acrylic). DK weight - couple of yards.

Substitutes: Any sock weight yarn for case which contains wool or synthetics; for the straps any DK weight yarn preferably made of elastic synthetics.

Hook
3.5mm (E) Crochet Hook

Other Materials (Optional)
20cm x 30cm piece of Sari material for lining (max size needed, I actually used 19 by 32)
20cm of 0.8mm copper wire & round nose pliers (for catch on case) OR a ready made hook & eye catch
Cotton thread (match colour to your lining) & embroidery needles
Pins
Scissors
Steel ruler

Gauge
The trinity stitch creates almost square clusters they are easier to count than fiddling around with where each stitch starts and finishes… I was working to approximately 3.5 clusters per inch. Gauge is not really that important as you will be working to measurements, but I have provided it here for people who would like to convert their measurements to stich counts.

Finished dimensions
For case & trim: Strecthed to fit DS = 15cm wide by 25cm long (give or take a cm for the single crochet trim) Maximum Stretch 17cm by 28cm. Unstretched 13cm by 22cm.
Straps: 21cm long (7cm to join) - unstretched length
Lining: cut to 19cm by 30. Hemmed to 17cm by 28cm (the maximum strech limmits of my case)

Key
sc Single Crochet
ts Trinity Stitch: if you do not know the stitch there are links to tutorials on my website
ch Chain
st Stich