I made a my laptop bag out of cotton fabric, ultra firm padding, plastic canvas and bias tape. I made it open lengthwise, rather than horizontally, and you'd be amazed at how much lighter it can feel carrying it, that way. I also put in a full-length cotton material separator between the laptop and upper side of the bag so that I could carry wires etc. without scratching my laptop. To complete the set, I made a matching purse with shoulder strap. It really makes a great statement!
I have abused it, most mercilessly, over the past couple of years, and everything is still in great condition.
And, I sewed almost all of it by hand. I'm a great lover of hand-sewing.