Gybing is definitely your friend. Here are quick pointers for successful gybing SIDES - HANDS - STEER - CONTROL.
First, Gybe when you are going as fast as possible. By sailing fast downwind you minimize the apparent wind speed and this minimizes the force of the wind "felt" by the sails. In 15 kts of breeze, if your hull speed is 3.5 kts then the wind felt by the sails will only be11.5 kts. A veritable calm!
Here are the four steps to gybing and NOT capsizing.
1) "Switch sides"
While sailing dead downwind, and paying close attention to maintain that point of sail, stand up facing forward and straddle the aft end of the centerboard trunk.
2) 'Switch Hands"
Hold the tiller with whichever hand is to leeward. If you are on a starboard tack then you will switch from your left to your right hand. If you had been on a port tack then you will switch from your right to your left hand.
Steer by using your weight and the rudder together. Slightly shift your weight, and push your tiller to windward . If you are on a starboard tack this means weight and tiller to starboard. On port tack - the opposite. The boat will now turn "away" from the wind such that the wind will catch the 'back side" of the leech and quickly push the sail across the boat. 4 letters spell a very important word at this point. D-U-C-K.
Moments before the gybe, I hold the mainsheet such that I am feeling the pressure exerted by the sail. At one particular moment the pressure gets light just before the wind will grab the back side of the mainsail and push it across the boat.. You will also notice just before that moment that the jib will start switching sides on it's own. Then I pull the mainsheet hard (even jerk it) to expedite moving the sail across the boat and simultaneously straighten the tiller (bring it to the middle of the boat). The tiller should ALREADY be pointing directly down the middle of the boat when the boom crosses overhead. This is one of the more important fine points that will prevent you from spinning out, heeling far over, and filling up with water as you capsize. Additionally since prior to gybing you already "switched sides and hands" you are perfectly positioned to hike out hard on the new windward side. If you need, when the boom is crossing the boat, you can even push the tiller slightly past mid position as you and your crew hike out hard on the new windward side.
There are still a few fine points to this process which involve more aggressive rolling of the boat and engaging the crew in helping to throw the main over. These will become important on the race course. However, for now start practicing what I have outlined here and you will be on your way to fast fun gybing in any wind condition.
Gybe early, gybe often.