I watched three Youtube videos to educate myself. In one, Bob Vila talked to a mason who seemed to know what he was doing. The man displayed his perfectly mixed mortar — a 2:1 mix of sand and portland cement — and delicately buttered the top surface of the CMU blocks in front of him. Then Bob Vila tried while the mason looked around for a grip with whom to share a wry smile. My own technique resembled that of a TV personality much more closely than it did that of an experienced mason; thankfully my boss thinks of his house as more of an art project than a custom home.