Be sure you buy concrete that doesn't have rocks in it. (So just ask someone at the hardware store, where you're buying it.) To make it all you do is mix water with the concrete and voila! We did two different batches. Aubrey made a thick batch, which made for a bumpier surface on the planters. I did a second batch and added more water to my mixture and the result was that the surface was extra smooth. Neither is the right way, both just give you different looks and are different to work with. (The runnier the mixture, the longer it will take to dry) Concrete is drying on the hands, so wear gloves. Aubrey didn't and his hands were pretty sore that day.