Could you please give step by step instruction on how to do a concrete countertop? I have looked at the info on stains, but understand they can be mixed in the concrete or added on top. How? Also, I purchased a sealer called Tilelab, Surfacegard Penetrating Sealer, with Teflon surface protector. Would you agree that this could be used effectively? It is for stone, marble, tile, grout and masonry. I would like to make the countertop coordinate with my tile floor colors. Is there a better way than buying a gallon of each color when so little is needed? Als, I know there is cementboard for counters. Would it be good to use it as a base, over plywood, and if so, how thick should the concrete be? Thankyou very much.