We always suggest that a crate should be nestled in between at least two (three is better) surfaces. If you can put it the corner against two walls that is great, if you can put it with two pieces of furniture on either side and the wall on the back- that is even better. Dogs will feel more secure in a tighter, cozier environment.
You can also hang a blanket over his crate if he is in a wire-crate. This will help create a more den like environment. Obviously, keep a close eye on the temperature as you don’t want him to get too hot in the summer months.
Put something in his crate that smells like you. An old shirt or a pillow case that you have used and are willing to part with will help him have you around when you are not really around.
If possible, put a classical music CD on repeat where his crate is. This will not only help to soothe him, but it will help drown out noises in the house that may be causing him to be anxious.
I am sure that his crate is a comfortable place, but do everything you can to make his blankets and bedding really soft and comfortable. A sleeping dog will not try to get out. I also suggest stimulating toys/ treats to keep him occupied when you are out. Kongs, Find the Squirrel, Puzzle toys, Bully Sticks, and Bones stuffed with Peanut butter are always great options.
Make a routine
Anytime you leave use a phrase like “kennel up” or “get in your bed” when you put him in his crate. He gets into his bed and you give him a great treat. You put the music, close the lights, and walk out of the room.
I often tell people if dogs are exhibiting any signs of separation anxiety (which may be the case with the dog trying to get out), walk out of the room for five minutes. Come back in and let him out – start the whole routine again. As soon as he learns that you will always come back, he will feel a lot more secure.
Make it his space
Leave the crate door open all day. You want him to feel like this is his little “room.” This is where he can go if he needs a break or wants to take a nap. No one is allowed to touch him when he is in his crate – it is his space. Make sure his crate is always opened so he can go in and out of the crate as he pleases when you are home.
If possible, hang out with him in the room that his crate is located. If you were able to watch TV in that room with him, he could associate that being in the crate doesn’t always mean that you are leaving. I also recommend having dogs sleep in their crates in your room with you. This also emphasizes that being in their crate does not equal my Mommy being gone.
Feed him in his crate
He will then associate being satiated with being in his crate.
Another great crating resource: http://www.humanesociety.org/animals/dogs/tips/crate_training.html