I thought it might help people to start a thread on this.
There’s a Facebook group called canine enrichment that has ideas for how to entertain your dogs and enrich their lives. Lots of the ideas relate to food - ways to challenge your dog in locating and eating their food rather than just putting it in a bowl
Brain training for 10 minutes is supposed to be the same as a half hour walk. There’s lots of info on google
Tossing balls in the garden or down the stairs
Freezing scraps of meat in water so it makes a giant IceCube and then giving it to your dog.
Lots of cuddles.
Anyone got any other ideas???