I went through this with my dog last summer

One thing I was told was that the crate should not be too big (just big enough for them to get up and turn around I believe).
Anyway, mine was way to big- I thought it was a good idea at the time to have it EXTRA big & cushy.

Also, don't make too big a deal when you leave or return home. I was told to kind of ignore my dog for 10 mins. or so when I firts get home. That way they don't attach too much anxiety to you leaving. It was VERY hard for me to do.

There are alot of people here who know a whole lot more than I do, and I'm sure they will chime in.
Good Luck!