One thing that helped with our dog and her crate was crating her, with a kong, while we were home and doing things like watching TV, reading, surfing the internet, cooking dinner, eating -- you know, normal at-home activites. We started crate training late in the game, and it worked by starting this way a moving up to crating her when we went out for a bit.
This let her make the crate a happy place that she liked going to, and did not just associate it with us leaving.
This let her make the crate a happy place that she liked going to, and did not just associate it with us leaving.