I thought I& already found the best example of a BILLY hack already —these built-ins from Gwen of Makerista, which we posted early last year. Then this project came to my attention, and I& made room in my heart for two loves instead of just one.
INTERIOR AMMM by architecture, via Behance - Narrow vanity alongside the tub. This is what we have only our sink is centered (way too close to the toilet). I was having trouble finding images of off center sinks in this configuration.