Which sail should you reef first when the wind gets up—your genoa or mainsail?
There’s no hard and fast answer to that one. Some sailors and sailmakers recommend first reefing the sail that’s closest to the wind; i.e., genoa before main if going upwind, vice-versa if going downwind. It all depends on the boat. For example, a 1970s cruiser-racer like an Ericson 35, with a large genoa and small main, would benefit from a reduction in headsail area before the main is reefed, while the reverse would be true for a boat with a large mainsail and smaller foretriangle, like a modern J/Boat. The only way to find out what suits your boat best is to experiment, so go out on a windy day and practice.