Ray explains the most efficient method. In the example I show above the bottom, front back and sides in first picture were the most critical surfaces of the entire part and they are all milled and finished. I always try to do as many critical sides as I can in the first cam offset. In this case I machined 5 precision surfaces from one offset and let the top of part be the wild surface and mill it to height and as parallel to the other 5 surfaces as possible in the previous setup. Then you have a decent 6 sided precision part to work on other sides with if required.

Add a note it also helps to use decent feeds and speeds and be careful with small diameter tool overhang. Was chasing a problem last week. I didnt have same overhang set in hsm advisor and at the holder on the machine. Had I entered that value correct in hsm it would have warned me your not going to be happy with results due to tool deflection.