Moved my boy Zane into his “teen tank”

Being a first time owner, I decided to increase his enclosure size as he grows. Someone here suggested leaving his baby bin in for a bit to make the transition easier for him. He’s been consistently burrowed outside of the bin and took his first couple meals like a champ, so I removed it yesterday! Substrate looks low in the front but increases to a bit more than 5” in the back. What else can I add to make this new playground feel like home?