My ideas usually come from my experience making toys for my birds. Even storebought birdtoys can be good for bunnies.
Here are some photos of Moo Shoo's toys.
That's the first bunch of toys I made for Moo Shoo, since they like to throw things around. He definately did enjoy that. I always have alot twine for making toys for the birds, and it's perfect for the rabbit aswell. Wood beads, whiffle balls, carboard. The red ring is actually an acrylic napkin holder. I got a dozen of them for like a dollar. Moo Shoo really liked throwing them around, and they also made good components for other toys.
That was a big spool of ribbon or whatnot, made of carboard, added some twine and wooden buttons, it was Moo SHoo's favourite for the longest time.
Those ones are really easy and cheap to make. Pack of wooden clips for a dollar, the colourful sticks come in a bunch of bundles along with square wooden beads all for a dollar, and some twine. Good chew toy and good for throwing around.
Essentially all of the components I've already mentioned, put together and hung up. I've recently found that Moo SHoo seems to prefer toys that are hung, so he can really go at them without them rolling away (especially since his cage has three levels and the toys can roll down away from him). He really likes things that jinle, so cat jingly balls work very well. A carboard tube cut upinto rings can make for a good component in a toy too, like you see there.
Here you can see.. on the first floor theres a large jingly cat ball toy, that was a dollar and he really enjoys chasing it around. It's extremely noisey though. I also like to give him small stuffed animals because they're cute. THe hippo on the key ring he really liked to chew on, so much so that I eventually took it away. He gnawed her arms completely off! On the top floor you can see a storebought bird skewer toy, he really likes that, and makes a huge racket with the copper bell that hangs from it!
REcently I've been hanging all of his toys. I got a big willow ring and tied his two animal toys to it. I also put in a bird perch toy that my birds ignored in there, because it has a bell, and attached a bunch of other beads onto it. Whiffle balls are great because you can stuff things into them, like hay, or even raisins, aswell as wodden sticks.
I also have photos of some really neat toys I made recently and sent to a friend in a 'secret santa' kind of game, but will wait to post those photos until she gets them, just in case.. I don't want to spoil the surprise. I'll post more photos after I move.. the rabbit and birds are getting their own entire room, and I will deck it all out with lots of fun activities and play stations for them.
I like the carboard box hut you made, I may steal that idea somewhat, and will be sure to check out the recommended link.
Moo Shoo likes hidey holes too, I used to give him carboard boxes in his cage, but then switched to just leaving his travel cage in his big cage, so that he's more comfortable when I do have to travel with him.