Left crosswinds are easier, start there. You’re probably already in a sideslip unless you know to counter nose-down P-factor with left rudder. Since most pilots don’t do that, they tend to have the left wing slightly down as they start the round out. Also, nearly every pilot yaws left in the flare (due to nose-up P-factor) so even if you can’t get the plane straight you’re probably nearer to the centerline.

Embry Riddle has it right: their students fly all the way down final in a goofy sideslip. How else are you going to learn to control a plane in a sideslip? If I were a CFI, I’d have my students correcting their runway alignment with sideslips instead of coordinated turns. When they got good at it, then I’d let them try some crosswinds. When they got good at that, I’d finally show them crab-and-slip.