All I have to say is use the field manual for Refresh, Regain, shell and protect. Every avatar that I've faced I used it and won.
I just summon carby, let him attack the avatar as I run away. I let carby die, and I'm far enough away to were the avatar has to run to me, so I recast carby and use astral flow. I let carby get hate, and use SL as I'm running away. I get far enough away (carby is still alive) and use a hi-pot and ether, when carby dies and the avatar is comming at you, you have plenty of time to recast carby, and let him get hate again, and use SL again. Depending on how fast you are, you can get a third SL in, but most of the time I didn't get the chance to use SL again, so I just keep summoning carby and beat the hell out of the avatar... :D
Congrats, you can easily get all the avatars with this method, its safe, effective and less time consuming.
ITEMS:
2 Hi-pots
2 Ethers
1 Yag drink
EQUIPMENT:
Hermit's Wand
Compound eye circlet
Justice badge
valor earrings X2
Baron's Saio
Scentless Armlets
Mist silk cape
Heko Obi +1
Mage's slacks
light soleas