What I do is make getting into the crate a fun and happy thing (in fact my dogs will now crate themselves early if I get ready to leave and then get distracted...).
I have a 'getting ready to leave' routine that I alway follow (um, except when I get distracted
) but part of that is the LAST things I do is go to the treat jar, get a treat (making happy pup noises and fun fun fun noises) and then run to the crate. Toss in the treat, pup follows and THEN I LEAVE IMMEDIATELY. While the pup is still chewing on the treats.
I know some people go even further and have a wonderful treat/peanut butter filled kong to toss in with their pup.
The important thing for me is the leaving immediately. Cause the NORMAL reaction for a NORMAL puppy when stuck and separated from it's pack is to scream like a maniac so the family knows where they are and they can be reunited. So if you are walking around the house and clearly (to the puppy, not realizing that he's not able to be with you) not aware he's 'stuck' he's HELPING by telling you the only way he knows how, I'm over here!!!!!!!!!!!!!!!!!!
The more REAL exercise, socialization, meet and greets, new sights, new situations, new smells, etc. you can offer to your pup when you are home. The more likely they will calm down faster and take a nap in the crate.
I have a 'getting ready to leave' routine that I alway follow (um, except when I get distracted

I know some people go even further and have a wonderful treat/peanut butter filled kong to toss in with their pup.
The important thing for me is the leaving immediately. Cause the NORMAL reaction for a NORMAL puppy when stuck and separated from it's pack is to scream like a maniac so the family knows where they are and they can be reunited. So if you are walking around the house and clearly (to the puppy, not realizing that he's not able to be with you) not aware he's 'stuck' he's HELPING by telling you the only way he knows how, I'm over here!!!!!!!!!!!!!!!!!!
The more REAL exercise, socialization, meet and greets, new sights, new situations, new smells, etc. you can offer to your pup when you are home. The more likely they will calm down faster and take a nap in the crate.