Warning: prompting for smile/grin/parted lips/teeth/etc. will probably make the shoe appear further away from the face. Make sure to exclude if you want shoe to cover mouth. Similar idea holds true for prompting large shoes covering eyes.
Prompting structure
holding [size] [color] {shoe type} to face
[size] [color] {shoe type} tied to face by [color] rope
[size] [color] {shoe type} taped to face by [color] tape
shoe types (shoes outside of list may not work well)
sneaker
boot
shoe
generic shoe used in training for hard-to-identify shoe
shoe sizes (may not work well)
small
large