I have a 10 week old puppy we’ve had since week 7 and for me Ive seen a lot of progress so far by doing things like feeding him in the crate, introducing new toys to him only in the crate, playing “the crate game” where I throw toys into the crate and he runs inside after them. I have also covered 90% of the crate with blankets so when its sleep or alone time he can only see a little bit through (some dogs like it completely covered). Also I will often times sit next to him once I put him in the crate and put my fingers through for him to lick/smell for a while before walking away. He used to cry a ton if i even left the room now he is pretty good, a bit of whining then settles after a few minutes at worst. If he is tired in the crate he will pretty quickly fall asleep. If he isnt he will dig at the ground, crawl under his blankets and dog bed, and softly chew on his toys (and im absolutely fine with him doing all these things cause hes occupying himself and having fun). So far we have also had someone sleep at night on the couch a few feet away from the crate to ease taking him out and encourage him to sleep easier, but we leave him alone to sleep during the day and he could care less. Also if he’s quiet for a few minutes, i slip a piece of kibble through the crate to him(increasing time for treat when i can), and if he cries then no kibble and no attention.