Hamsters tend to like simple things like egg boxes, tissue boxes, toilet roll tubes etc... hanging toys I wouldn`t bother with as hamsters shouldn`t climb. Placing things around the cage or inside tubes, scatter feeding and having a small shelf they can clamber up onto are all good. A shelf can be made from a simple piece of household shelving made from untreated pine. DIY stores sell untreated corner shelves made from pine and these can be made into cage shelves, but using a small strip of pine sawn from a shelf or a small piece to fit inside you cage from off cuts would do.
Screw four legs on each end using a drill and only make the shelf about the same height as a long tissue box that can fit underneath. Use the box as a guide on how long to make the legs. You don`t want it higher than about five to six inches off the ground.
Just use flat headed screws down through the shelf and into the wooden legs to hold. That`s it.
You can then just hook a Trixie bendy ladder on and you have a safe, solid ramp. I use an old Ferplast internal shelf inside my Gabber Rex tank cage and Chub`s sleeping box is directly under it. Finding a spare one would mean just sliding it between your cage top and base as it has little inserts that fit between the cage parts. x