Re: jibing correctly?
Good points from Faster above. also when the boom passes over your head, it's time to move the tiller back to midships. Beginners and inattentive helmsmen sometimes leave the tiller over too long, and are no longer headed downwind when the boom comes over, they're on a reach on the new tack. Easy to lose control this way in a breeze, you round up and broach.
I once did a chicken-jibe while defending a few boatlength lead in a race at the reach mark during a squall. Yeah, i felt chicken all right, why couldn't I be a Man and jibe?
Well, I learned why. Second place boat tried the jibe and broke his mast. Third boat, and all following, did the chicken jibe. I held on and won. Got thanked at the evening cocktail party, too.
This was long ago (the masts were spruce) but the principle is still the same.