- Storm Step
- Cross Cut
- Double Cross
- Smash Mastery
- Battle Respiration
These skills will most likely be your most predominantly used skills - max them (or get them to rank 6 / as high as you can ASAP). Bear in mind that you're not going to get these skills straight out of the gate, and will have to get a bit into the game to get them.
- Combat Mastery
- STR Mastery
- AGI Mastery
- WIL Mastery
- Individual smash skills - Tumult, Gale, etc
- HP Potion proficiency
Your stat masteries are a high priority, but not the highest - same goes for the individual smashes - they boost your overall damage, but are not the most efficient way of doing so (STR Mastery aside). Potion proficiency is a good way to get more out of your HP pots, get to rank 9 if other skills are at a reasonable level.
- Light / Heavy / Plate Armor Mastery
Not pressing - rank these as you need them (i.e when an item you want to wear requires a certain rank in one of these skills.
Mixed bag. Typhoon Slash is mostly worthless (for now, at least - I hear Sword Vella revamp will maybe fix that), Slashing High is a good skill not a priority at lower levels, Tempest is a high priority that should be maxed ASAP.
Of course, these are my own opinions based upon my own preferences - you (and everyone else) are fully entitled to ignore, or question, these opinions if you feel they are wrong.