Use drawer slides; mount the drawer on the wall; attach the shell to the slides, so it pulls out. Shifty Desk / Hallway Stand by Daniel Schofield This is such a great storage idea! It can be a shelf and a drawer.
Kitchen Storage Tip: Store your utensils diagonally instead of flat in vertical or horizontal slots. A diagonal insert makes a smarter, more efficient use of drawer space. Shop the MarthaStewartLiving collection at The Home Depot for space-saving solution
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.