Reefing - Genoa and/or main first

[Gunfleet]

Doesn't it depend on the boat and crew? Single handed or with inexperienced crew, reef if there's the slightest possibility of needing to. Reef at night as a matter of course, unless there's no chance of the wind getting up. With a roller headsail you might never need to leave the cockpit in darkness. That aside it's all about balancing the helm, so depends on the vessel. I think that's what the variety of answers above is telling you.

 

[Rossynant]

Course sailed is a factor. Going upwind reef in headsail first makes sense because it also reduces heeling force from main - the upper part of it loses flow (when there is no headsail before it). So it's recommended way; unless it makes a weather helm. But on a reach i'd guess it doesn't matter, and many boats handle better with reduced main off the wind.