The tramp pocket set up I like is one I made for my boat two years ago. I used tramp material, which was as wide as I wanted the pocket and twice as long as I wanted the finished product. I then folded the material to form a pocket. I then inserted a piece of two inch wide webbing down the sides and sewed this to the pocket. Another two pieces of webbing on each side of the mouth of the pocket and then turned it inside out, so the sewing is on the inside.... and then I added grommets on the corners and every six inches or so along the sides of the webbing. These grommets are added so I can affix the pocket to my tramp, when I want it and when I don't is stashes easily in the car or elsewhere. This arrangement is simple to sew because one isn't having to mess around with the big tramp on the sewing machine...and it isn't a permanent on the boat's tramp...which makes it lots easier to replace, reconfigure, make bigger or smaller or move forward or aft as one's needs or vision changes. One can also sew cinch straps on the pocket to allow it to be expanded or contracted, depending on what all one may have in it.... and as I see it.... adding a few grommets to the boat's tramp is lots easier than wrestling with it on the sewing machine and trying to sew on a pocket and having the pocket not stitched too tight or loose, compared to the tension of the tramp when it's on the sewing machine and when it's tensioned on the boat.
Just another idea for you to consider.
Tom H.