This takes a while and you have to start when you first get GFs, but It REALLY gives you a head start.
If you collect the cards then you may not want to do this!

RED numbers are essential for this to work
GREEN numbers are optional

--Balamb Garden - Dollet
1, Learn Card then Card Mod- Quezacotl
2, Learn HP-Junction
3, Try to beat Diablos before Timber but this is not totally essential.
3, Learn Time RF (No enc. can wait seriously!!!)
--Timber - Deling City
4, You MUST get Brothers from the Tomb of the Unknown King.
5, Card mod the Brothers Card into 100 Dino bones then Use Diablos' Time RF to Fill everyones Magic with QUAKE.
6, Card Mod Diablos' Card into 100 Black holes and Then Use Diablos' Time RF to fill everyones magic with DEMI.
7,Junction The QUAKE to HP, and the DEMI to Magic or Strength. This should boost your HP up to over 3000 HP and you strength to about 50-70. depending on your level.

This teqnique is a great way to help in battles if (like me..) you happen to be a bit lazy in the levelling up department.. This is also good because it can help for the whole game. No cheats. No codes. Just a clever use of abilities.