When installing a sink, consider using flexible supply hoses and adding mold- and bacteria-growth-inhibiting latex caulk to the lip of the sink to produce watertight seals. Also, never reuse flexible supply hoses because the rubber gaskets often harden, preventing a good seal between the hose and the sink. Use flexible hoses outfitted with new rubber o-rings, which allows you to skip the use of sealants or Teflon tape.
Before installing the kitchen sink, install the faucet, sprayer and any liquid soap dispensers while you have easy access to the mounting nuts. Use plumbers' putty to create a seal between the faucet and any other items and the sink.
Pick a replacement sink that matches the current opening in the counter. Larger sinks are also acceptable, but it can be difficult to enlarge the hole in the countertop for some materials. Use a jigsaw or circular saw to cut a new hole in wood or laminate countertops.
If you install the sink into a new countertop, be sure to use the cutting template supplied by the sink manufacturer. If there is no cutting template, turn the sink over onto the countertop and trace around the edge. Then, measure the lip of the sink, and draw a new line that diminishes the size of the hole on all sides by the width of the sink lip. Use the second line as the guide for the sink hole.
Clean a new sink before installing it. Stainless steel sinks, in particular, can smell when they are brand new, and it is easier to clean the sink before installation.