You want to talk to Malivox, in the NW corner of the sandstorm south of Tulimshar.
My main is a level 85 archer, so I know what generally effective stats are:
- Focus Mallard's Eye, of course. You can get up to 8 range with no loss of accuracy with Mallard's Eye 9 and DEX 100. This makes a big difference because there is a damage penalty for being too close to your target.
- DEX: 100 points exactly, including armor bonus. Any less and you lose damage and accuracy bonuses, as well as the full effect of Mallard's Eye; any more is just a waste of points.
How to get the extra point, from worst to best:
- Forest armor: +3 bonus, but least effective armor. Useful in the early game to increase damage quickly without using stat points, but useless later on.
- Terranite Chest armor: +1 bonus, decent armor. I recommend getting this before the ring even though technically it is more expensive, just because it's good training.
- Amethyst ring: +1 bonus, doesn't take an armor slot, so you can use warlord plate.
- VIT: As many points as you need. I have 32, which is enough to take a few hits and give me time to run and heal at a decent rate.
- LUK: As many points as you need. I have 29 (30 with my 4-leaf clover, but I keep swapping that between my characters). This is enough to reduce the frequency of enemy critical hits so hopefully I won't get 2 in a row. After all, as an archer, you're not supposed to be close enough to the enemy for them to hit you.
- AGI: everything else. Note, terranite leg armor is +1 AGI. Note that Cat Ears has a +3 bonus, but I don't use them (+18 defense with Warlord Helmet is nothing to laugh at). I have 78+1
Though actually it has been a while since I fought Yetis, I think you might need a higher VIT/LUK. But, that was before they (accidentally?) weakened Yetis by slowing them down, you might be able to avoid them effectively even in the narrow caves. Also note that, with the high Damage Resistance of Yetis, it is worth using more expensive arrows. Back when I was fighting Yetis this mean Iron Arrows rather than regular Arrows, but there are more options now (Bone Arrows, Terranite Arrows since you're past 80)
Former programmer for the TMWA server.