A granite vanity top is a smaller project than a kitchen, but the same rule applies: the cutouts are only as good as the information we have when we cut. A few decisions up front make installation smooth.
Start with the sink. Undermount sinks give a clean, modern look and make wiping the counter easy. Vessel sinks sit on top and need only a drain hole. Drop-in sinks are the simplest to replace later. Have the actual sink on hand when we measure.
Next, the faucet. Single-hole, centerset, and widespread faucets all need different holes, so pick the faucet before fabrication. Wall-mounted faucets need no holes in the stone at all, but the plumbing has to be planned before the wall is closed.
Finally, think about splash pieces and size. A matching granite backsplash protects the wall, and side splashes help where the vanity meets a wall. For smaller vanities, a remnant left over from a larger slab can be a cost-effective way to get natural stone in the bathroom.