Long ago, I made myself shoe bags for travel. I never used a pattern. I used a polyester blend "bottomweight" fabric. That way, they were going to be durable. If you really had your heart set on lightweight cotton, then you should by all means line the bag.

To determine the size, measure your shoes. Better yet, measure the box they came in. You need to have a box that holds the shoes without extra room that would allow them to jostle against each other. If you measure the circumference of the box, that ought to give you a good size to allow you to slip your shoes through the opening easily, yet not be so baggy that the shoes jostle against each other.

I found you a tutorial, in case you want instructions for making a lined bag.href>

You will probably want to start by viewing the instructions for the unlined version.href>