First off, this is my first 'How To' so if there are any questions feel free to ask. Pick out a couple of fabrics you like. One preferably fleece or flannel or something of the sorts that's soft and will offer a lil bit of padding. You can always add quilting or a heavy interfacing i guess.

Measure, Measure, Measure. The best way that worked for me for adding in the height was to lay my laptop on the edge of the fabric and wrap the fabric over and mark it leaving about a cm or so for seams. This will include the height and width. Then you can determine the length you need depending on how much extra fabric you wan at the opening.

Cut each piece of your fabric. I used one piece of each fabric so there were only 2 sided to sew up.

Put the 'bad' sides together, fold the outer fabric over the fleece about a cm where the top opening is gonna be. Sew to get rid of frazzled edges and have a clean finished look.

Now fold like a tube with the 'good' sides together. Pin and sew. Don't sew the bottom together yet; you may have to make changes.

Slide your laptop in to your tube to make sure its fitting snugly. If its the fit you want, pin and sew the bottom. If not, go back and re-sew so it fits the way you want.

Flip right side out and viola.. a fast, easy protective cover for your laptop.

If you want to add a pocket for you power cord or anything else I suggest doing it between 4 and 5.