We are having our first experience with chin babies too. It can be very unsettling because they are so loveable so quickly. I have noticed that ours like the cage rearranged ever so often. I move the basket from one end to the other, hang the water bottle in a different corner, that sort of thing. Also I add and delete cardboard tubes, half boxes with lots of holes for climbing through, and bits of kiln dried, non-treated for bugs, pine from the local small hardware store. When we have floor time, we bring different things along. Sometimes empty orange crates, sometimes empty boxes from canned goods, sometimes lots of saved empty paper towel rolls. I just change it up a lot, so playtime is always different.
I have also noticed when I am worried or upset they seem to pick up on it. She gets grumpy and he gets snuggley. Of course I understand both feelings
Another thing we do is keep on the lookout for new treats. No sugar, only Chin safe, but there are a lot of options out there! The only thing I don't change around is his/her potty corner, since that is not my decision to make,lol.
I hope this helps, I know each Chinbaby is different (as is each Chinmom and Chingrammy). Good luck with your Babe and his moods.
The more I learn, the more I realize how little I know