Use Sky Blow. It doesn't consume any spirit sphere.. and then use Focus Beret so that you can spam the skill. Once you reached Level 150, get Grace equipment and use Noblesse Oblige ring to boost sky blow damage. I just recently did sura levelling and it's fun to use Sky Blow
For Level 115 and above, your best spot for levelling will be:
- Juperos 01 (until up to level 130 for bounty board)
- Outside Scaraba Dungeon (all the monsters here have El Discastes and Manuk bounty boards)
- Then get to Nightmare Clock Tower, then level 175 and above boards that will get you to 4th job and beyond
Once you have money eventually, the end game gears shall focus on reducing Tiger Cannon cooldown and increase it's skill damage
Or save up by buying Sky Blow Ring x 2 if you're still interested in Sky Blow build