When I went through air traffic control school I was taught, since the pilot sits on the left side of the aircraft, standard turns in a traffic pattern were to the left so the pilot can keep the airport in sight. Conversely, standard turns in a holding pattern were to the right so the pilot could see the airspace outside of the holding pattern. I’ve put many aircraft into a holding pattern and the few times I required the aircraft to make left turns I had to state “left turns” in the holding clearance. Absent any instructions the pilot will make right turns. source FAAO 7110.65W, para 4-6-4e.
I know, but I always liked left turns, (and often request them if terrain or other traffic is not an issue) so I can “see where I’m going” especially if we are on an IFR flight plan, but holding below FL 180 in VFR.