Mandatory Stats: Make sure to fill out your resist, you want 75% fire/cold/lightning resist. Chaos resist is good, but not mandatory to have 75%, I usually aim for 30-50%. You'll also most likely need 1-2 attribute rolls on gear, belt will solve strength and if you need intelligence, get it on a ring or amulet.
Hybrid swap: You want the highest Energy shield helmet you can afford and a very high evasion chest to make
Ghost Dance effective, as it's your only way to recover ES. I would also try to get good hybrid boots. You'll probably need intelligence on helmet to have enough attributes.
Rings/glove: try to focus on high flat damage to attacks, preferable cold/phys.
Bow: When swapping to crit, you want a high crit bow, preferable with t3 %crit or higher. (3% or more). After that, get the highest dps you can afford or craft.
Quiver: You preferable want a crit quiver on the
Visceral Quiver base. You'll want both crit hit chance and crit damage. Good prefixes are bow damage/proj speed/cold damage to attack/phys damage to attacks.
Cadiro's Gambit is also a really good quiver and highly worth getting once you can afford it (I would only use this quiver if you're crit).
amulet: Preferable want +proj levels. Crit chance/crit damage is also good, once you swap to crit. Attributes/resist are also fine here. You need at least 45 spirit on the amulet to use all spirit gems. Crit on amulet is also strong, but might be expensive with spirit and +3 proj.
Helmet: It's very important to have a high ES helmet because of
Subterfuge Mask.
Chest: you want the highest evasion chest you can afford, this is very important for defense, specially when combined with
Beastial Skin on the passive tree. use
Greater Iron Rune
Boots: You want the highest movement speed boots you can afford, it's a very important stat. Besides that look for high life/resistance.
Belt: Not a lot of choices here, just Life/str/resist, eventually you want to get a
Headhunter.
Rarity: Still really good in 0.5, I would try to hit at least 100% if you want to farm efficiently (don't focus on this if you feel like you're lacking damage or defense)
Jewels on tree: Just looking for generic damage: attack damage, elemental damage, movement speed, bonus from quivers, projectile damage, attack speed, crit chance, crit damage, etc.
Eventually you'll also want
Heart of the Well with double "gain as extra" and
Against the Darkness with double again as extra as well.
important:
You'll want 1 sapphire jewel with mana on kill to sustain mana during mapping. For bosses, having Mark of Siphoning II on
Freezing Mark with Eternal Mark should give you enough sustain.
Anoint:
Climate Change or
Beastial Skin for defense
Serrated Edges is always a cheap option.
---Mana Issues
There's a few things you can do here to help out your mana sustain and I'll list them all here.
Reminder: Always run one jewel with 2% mana on kill.
1) Run a regular mana flask with increased recovery and just use your mana flask button, this along with a 2% mana on kill jewel will easily sustain you
2) Take
Conservative Casting for 3 passives points.
3) Drop
Wind Dancer for
Mana Remnants (use Harmonic Remnants II, Remnant Potency III and Khatal's Rejuvenation - For khatal you either need Dialla's Desire as well or 1 point into herald reservation