What general approach should I take in fusing? Should I be pretty conservative or just go all out and experiment with Fusion?
It's best to fuse every few floors, I think. When you get a new Persona in the shuffle time, stock up on new Personas, take them down to Igor and try em out.
When it comes to fusion, I think it's most advisable to have a few specific types at one time. That way you can overcome any situation and not be thrown for a loop. ie: have a agi persona, garu persona, bufu persona, and zio persona. Even better is a persona that has all 4 elemental types - which you can mostly only make through fusion experimentation. Physical (attack) based persona are also great, because some have null or repel when it comes to physical attacks. That means every time someone hits you with that persona equipped you block or send back their attack. Very useful, especially on the boss of the second dungeon. Later in the game it's advisable to make, on top of the four basic elemental Personas, light and dark based personas so you can cover your ass and not get a game over whenever a shadow hits you with an instant death spell. But it's still quite early for that so...
Also, one other tip is to make use of buffs and debuffs.
There are two types of buffs in the Shin Megami Tensei games: unda and kaja spells.
Kaja - buff which strengthens a character or the whole party
Unda - debuff, which lowers enemy power
Notable starter buffs/debuffs:
Rakukaja - Improve defense
Rakunda - Lower defense
Sukukaja - Improve hit and evasion
Sukunda - Lowers hit and evasion
Tarukaja - Improves attack power
Tarunda - Lowers attack power
Dekunda - Nullfies all stat changes (buffs/debuffs) on party
Dakaja - Nullfies all stat changes on enemy
