Lifesiphon's are for sure a good craft. Other than that, it really depends on the kind of relics you have. Do you have the popular things like Platinum Sword, Onion Gauntlets, Sentinel's Grimoire or Thyrus Staff? What kind of medica's, if any, do you have?
As a general tip, you want a team something like Healer, Support, Dps, Dps, dps/support hybrid. Some of the staples you should work towards are:
Shellga/Protectga rank 2
Curaja Rank 4-5
Fullbreak rank 2-3
Power/Magic Breakdown rank 3-4
Lifesiphon rank 3-4 (maybe 2 copies)