Recycling cardboard boxes. I tie a rope to the box (the ones with holes) and use it as a flirt pole. Tons of fun in combination with training impulse control!
He pulls pieces off which gives him more drive and I break it up with releases, down stays, sit stays, "tug!". Then at the end I pick up the pieces while practicing "Leave It" and again the stays and "Done"!
Another one: putting a couple of treats or a toy in a closed cardboard box and let him rip it apart.
Recycling plastic jugs: same or I just give it to him under supervision only to prevent him from swallowing, which he never has done so far.
This gives him new toys all the time and me a content dog.
Deja, GSD, sable WL, female, born 11 / 2013
Cam, Rough Collie, sable, male, born 8/2015