-
We got a big length of vet bed for the bottom of the crate to make it cosier & there's always a blanket over the top for extra den points too - if it's hot how about an old bedsheet?
Mavis sleeps in our room in her crate but is going into the one in the living room less now, at first she'd go straight there if she wanted a nap, but now she tends to just curl up on the couch - I don't know if we should discourage this but if we're going out for an hour or two she seems happy enough in her crate then with a pile of the good treats dotted around.
This has been great for peace of mind too if we're popping out
There's a good facebook group called "Dog Training Advice and Support" that's run by some pro trainers and has loads of resources. They're very much positive reinforcement only and their method for crate sleeping is if the dog is whining sleep next to them and build it up as they get more used to being in the crate and doing crate training so they see it as a positive place.