Check out this adorable custom foot rig designed for characters wearing removable shoes, created by 3DCG Artist and Rigger GACCHI.
Set up with Maya in combination with the mGear rigging framework, the rig allows for switching between wearing and removing the shoes by tweaking parameters in IK Ref, as the artist explains in the video above.
GACCHI is renowned for stunning highly detailed artwork, such as this fluid hair rig for a digital model of Fern from Sousou no Frieren and a recreation of one of the shots from Sousou no Frieren's first opening in 3D: