Some odd notes: Grand Slam can be learned from using Rock Crush in group battles. It attacks all enemies, but the damage doesn't actually take effect until the end of the round

  Spear   

Some odd notes: Wide Swing is learned in group battles... however it doesn't seem like any one tech learns it faster than others. Normal attacks will learn it just as fast as Brain Shaker or Aiming. Either way, it's only learned in group battles.

Axe  

Some odd notes: Axes suck. Part of this is because Axe TECHS suck. Tougher to combo, large gaps making them harder to learn, generally weaker than Swords or Spears, not much in the way of special effects. If your character has ANY other decent weapon proficiences (A good example of this is Primiera), I would not suggest using an Axe.

Bow  

Some odd notes: Random Arrow is...learned at random by other weak techs, and Arrow Rain can be learned from using Random Arrow a lot. Arrow Rain does not deal any damage until the end of a turn. Bows are mostly Quells and very magic reliant, so ideally, one would have Bow-proficient characters use a lot of magic. Likewise, it is very important to learn and focus on Hybrid Arts with bows.

Martial

Some odd notes: Ogre Run can be learned by various techs in group battles; there doesn't seem to be any one tech that learns it quicker than others. The same holds true for Dragon Revolution, though slightly higher level techs work better than lower level techs, since it IS one of the strongest Martial Arts techs