When I make a card slots I have a folded piece of cloth ( like silk something thin) behind it to keep the cards from sliding down.The cloth is glued down first at the bottom and glued a the the top of the first slot.The cloth is folded half the way down of the first slot from the bottom( I usually use a card to make sure it is where I want the top of the card to be ) then is glued down there to the cloth already there and glued then at the top of the next slot I glue it and I fold it again half the way down the second slot and glue it down and fold and the glue at the top of the sec slot and so forth untill I reach the top. Then it gets stitched across the slots and top and then I place it in the wallet's liner and stitch the bottom and edges. You don't have to stitch across the slots unless you want to.Once all pockets flaps ect are attached to the liner it gets glued and stitched to the wallet body. I hope this makes since. Your making pockets behind the slots.hope this helps.