You can mount the sink on a pedestal or choose a cabinet with an opening designed to accommodate the drain assembly.
If the bottom of the vessel sink is flat, you can mount the sink flush to the surface, using a bead of silicone around the seal to prevent water from working its way underneath the vessel. For sinks with rounded bottoms, a mounting ring elevates the sink and helps with the stability and the seal around the drain. Mounting rings often come with the sink, or can be purchased in a variety of finishes to match the faucet and drain.
Recessing the vessel into the countertop will provide a greater degree of stability. The larger the hole, the lower and more secure the sink will be. To experiment, you can cut a piece of cardboard the desired size of your hole and place it inside your sink. This will show you the approximate depth your sink will sit. Be sure to keep the height of the faucet in mind when making this decision. Once you’re selected the proper sized hole, you'll want to bevel the edge of the opening and seal around the outside with clear silicone.
If you're installing a glass vessel sink, you’ll need to provide a cushion between the glass and the counter, such as a bead of silicone or a rubber seal. Over-tightening the drain assembly can break the glass vessel, so hand-tighten only and follow the manufacturer's instructions for installation.