Keep in mind, more creative effects can be accomplished on the smaller counter areas than on commercial floors. Feathering marble veins, for example, is much easier on a small surface. Keep a piece of marble or pictures handy to use as reference as you develop the techniques that work for you. Water base stains work really well here. The super fine aggregate of a micro topping is also helpful to get a glassy smooth finish.
Topcoats are necessary to protect the concrete from stains.
Reapply waxes every week or so. Many people think only water base sealers are USDA approved, but Super Diamond Clear, a solvent sealer, has an Incidental Food Contact rating. Other top-coats are 2 part 100 percent epoxies and urethanes. These sealers require mixing and can be less forgiving in their application. Expect at least 5-10 years of service from the sealers, especially when owners use hot pads and cutting boards.