The best hint - gybing successfully is about apparent wind speed.
My hull speed is just over 7 knots. If there is 25 knot wind there is 18 knots of apparent breeze blowing in my spinnaker. If I can catch a wave and increase my boat speed to 11 knots I now have 14 knots of wind pressure in my sail. (3 knots makes a BIG difference).
NOW is the time to gybe. The best time to gybe in a blow is when you are traveling fastest (less apparent breeze in the sails).
In a blow, you travel fastest surfing down a wave. The helmsman must almost sail by the lea. We gybe the kite first using the main as a bit of a wind buffer ever decreasing the wind in the spinnaker. Once the spinnaker is set, pull the tiller across. As the boom starts its gybe quickly move the tiller back. This keeps the boat under the sails. From the air, the boat looks as if it has made a small "S". Now trim the gear.
Initially it goes against all your feelings of self preservation and the belief that the slower you go the safer you are. Also if you are only surfing for 30 seconds or so, both you fore deck and **** pit crew ans skipper have to know what they are doing and be coordinated!