First you need to chose your fabrics. One for the lining and one for the outside. So that I can quickly make lots of these I also made a 6" X 7" template/pattern.
Sew all the way round leaving a gap on one of the 6" sides (remember to backstitch these)
Press with an iron so that you get a nice smooth finish once its all stitched together.
Now chose which fabric you want to be on the outside and which will be the lining...
Top stitch each end (not the sides you have already top stitched)