Every once in a while you get a new mattress. In case the old one is not in a bad shape, here is what you can do to make your dog happy.
Cut the mattress into some shapes you'd like to have. You can use an ordinary kitchen knife for this. We went for 2x 1/4 circle and 2x squares.
This is only working with foam mattresses, not with innerspring mattresses.
A good friend sewed some cases and bottom covers for the dog beds. Make sure you get thick fabric, so the dog's claws don't rip it open.
Here is the one in front of our fireplace.
Another one next to my desk
The third in our kitchen.
The last in my basement-workshop.
But it is still the best thing to sit, sleep & play where humans use to do that...