Many lightweight tents either lack pockets or have unsuitable ones. There appear to be no easily available after market ones. I was looking for one for my Tramplite and came across the Montbell UL Paper Pouch, At 6g it’s very light. The grosgrain loops at either end of the zip means that it’s easily attached to an inner tent with safety pins. Using safety pins means minimal damage and flexibility in moving it around. Quite a neat solution, although not cheap!