Hi everyone. I'm going to pour a couple of caps for some block posts I built, but I'm not 100% sure of the mixture I should use to ensure I end up getting a good, solid and smooth cap. I know about needing to use a release agent such as motor oil or diesel fuel and making the form is not a problem either, I'm just looking for a formula for the actual cement material. I've heard portland cement and sand can yield good results. Any suggestions are appreciated. Thanks.

5000 psi bagged concrete from HD,mix at 4" slump, steel reinforcement and curing/sealing compound.
Good Luck!