This is a good video for making toys from toilet rolls too
https://www.youtube.com/watch?v=NuPeyD6w-CI
Depending on your cage, other good toys are rat sized things. Rat sputnik
Nobby Sputnik, Extra-Large, 29 x 26 x 19 cm: Amazon.co.uk: Pet Supplies
Medium 10cm chew tube
Boredom Breakers Chew Tube Medium Pets Small Animals: Amazon.co.uk: Electronics
Lots of deep substrate for digging tunnels is something hamsters like too
Ours also likes this little lava ledge to sit under. He climbs on it out of his sputnik too because I put food on it
. You can make steps with 2 or 3 of these
Kaytee (Was Superpet) Lava Ledge: Amazon.co.uk: Pet Supplies
My favourite is this kebab kabob. I changed the ring at the bottom to a bigger one though as I was worried about a foot getting caught in the small ring. I just used a standard keyring instead.
I hide treats on it and Charlie jumps up at it to get them and makes the bell ring.
Small 'N' Furry Treat 'k' Bob for Small Animals
To be honest the best thing you can get your hammy is a big cage with deep substrate so they can dig some tunnels and have lots of hidey places and space.