Easy ways to build limit breaks

Limit breaks are easy to build. When you have the first limit break of a level, to achieve the second of that level you need to use the first limit break at least five times. The easiest way to do that is to fight on the wutai continent and manipulate the birds that use lightning damage. Be sure to have your characters in fury so the limit gauges fill up quickly. when you achieve the second limit break of a level you must kill at leats 100 ememies. The easiest way to do that is to go to the in the forest above fort condor and fight the enemeis there because they come 5 and 3 at a time. and thats a rap

If you want to build your limit (not learn new ones but charge an existing technique), I recommend the following strategy:

1) Go to Junon Airport (late in the game), where you will be attacked by SOLDIERS (2nd or 1st class, can't remember which). Have the person charging the limit in Fury (induce with Hyper if necessary), and have your other two teammates armed with Big Guard, Cure3/Regen, Berserk-All, and a nasty spell like Ultima or Comet2. Have the person charging the limit equip Cover.
2) Cast Berserk-All on the soldiers. (If you get a rocket launching machine just kill it and try again, it can't be affected by Berserk.) It may take several casts to get all the soldiers Berserked.
3) Cast Big Guard on your enemies (to give them Haste and speed the process up). Cast Regen on the person charging the limit; cast Cure3 if additional healing is necessary.
4) When you've finally got your limit ready, have somebody cast Ultima or something. Walk away happy ready to Omnislash someone.

Just progress through the game... *<_<

I always just use Hypers as soon as I get them, and keep Fury status on. Then just progress through the game normally.