This cement floor is 100 years old. I stripped it bare to the bones by using muriatic acid (the newer, 'greener' type).
This garage floor has actually been converted into a full use kitchen and my client wanted it to feel more like that.
We agreed on a Tuscan look (since she's Italian and loves to cook Italian!), so I first applied a yellow stain, let it soak in, then used a rough staining brush to smack around some Terra Cotta color on top of the yellow.
Here's a close-up of four corners of the now-stained cement slabs meeting...
Following the final stain coat, I applied a clear, water-based protective satin finish (a type of polyurethane meant for durability on flooring surfaces) that gave it a beautiful, utilitarian lustre.
In the laundry room attached to this garage, I applied two different blues to achieve a different look than the kitchen floor adjoining it:
The stains I use are from a company called, MASON'S SELECT (see side panel for contact info for them); clear floor finish is Benjamin Moore's BENWOOD Floor and Wood Finish, Satin (see side panel on this page).