I used a wire kennel with my girls and draped a blanket just over the top and sides. I placed toys, treats, and a soft blanket to lay on and left the door open all the time. I would occasionally lure them in with threats or toys and let them freely come out. When I had to place one of them in thier crate I always gave them a treat as a reward.
Now, Cooper is the only one that still uses her crate and she will run into it when we go buy thinking she will get a treat.
They catch on quick with goodies as rewards.