This strategy is one of the most commonly used Protoss strategies. It is devestating, but does not require many skillz to do.

-Build 4 stargates, 2 cybernetics core, a forge, and a fleet beacon
-If you really want to annoy your opponenet, and have the time and money to, build an arbitor tribunal, and a 5th stargate.
-Before you start building any carriers, upgrade carrier capacity, air weapons, air armor, and plasma shields.
-Build a robotics facitlity and an observatory, and 2-4 observers.
-As soon as you have the money, build a carrier in each stargate.
-Also have a probe build a lot of pylons, because you're gonna need them.
-Continue building carriers and interceptors until you have 12 fully loaded and upgraded (3 weapons, 3 armor) carriers, and a few oberservers.
-If you have decided to use build an arbitor or 2, keep them in the back of your carriers. This cloaks the carriers, and protects your arbitors.
-Attack your opponent, and since units always go for the interceptors, there isn't much he can do.