The Heron had landed on a small crop of dead vegetation close to me. I’m not sure if the bird thought I couldn’t see him, since he froze after dropping down.

I followed rule 101 and grabbed the first images I could. The rule is take the shot, you may not get another chance, deal with setup after.
He stayed and then I decided to take my time, focus on his eye, and set up for a portrait style.
He very nicely posed all the while.