I can give you my opinion, although I’m not an expert. Probably the more experienced people on the forum will give you even better pointers. Finally, “what to look for” could be quite subjective, so I can tell you what I look for.
- Max resistances.
- 100% reflection damage reduction, so you won’t have to worry about reflecting enemies, especially in groups where you can’t isolate them. I achieve this with 2x Titan plate components and one or two constellations.
- Max damage bonus as much as possible for your final damage type.
- Convert as much damage as possible to the final damage type. Conversion applied through skill modifiers to a default attack replacer (like Righteous fervor, but with the exception of Cadence, which is broken as a DAR) is carried to all the attacks triggered by it (like Smite), so it’s easier to aim for the conversion of the DAR, instead of every single one of the triggered attacks (WPS). Or you can convert everything with global conversion.
- Try to get one effect for each of the defensive/offensive layers, such as “reduced enemy damage”, “chance for the enemy to miss attacks” etc. But not more than one because most of them don’t stack.
- Try to get above 2.8k offensive ability if you have skills that trigger on critical strikes. Or just try to do that in general.
- Try to add as many skill modifiers as possible from gear to your main skill(s).
- Internal damage scaling (done in the skill’s nodes) is more important than having slightly more global damage scaling.
- Try to apply as much lower resistance debuffs as possible to your damage type(s).
- Try to increase your health to at least 18k.
- Life steal is essential for survival. Some skills have inner life stealing, while the ones that have % weapon damage can use the global life stealing bonus.
- Try to have fewer and more powerful active secondary skills, so you won’t feel overwhelmed by constantly activating more than 3 or 4 of them.
- Your main skill usually (if not always) has to be without a cooldown, so you can spam at least one attack. You either choose one that doesn’t have a cooldown or you eliminate the cooldown with the skill’s extension or skill modifiers from gear.
I’m going to edit this response if I missed anything I couldn’t remember. I find it easier to look in the item database for skill modifiers and start from there. Once I identify a skill that’s modified nicely by gear, I build around that skill. I also look in the database for gear that helps me convert all damage to the final type. I either find gear that does a 100% conversion first and then look what skills would benefit from that or the other way around.
Here’s an example of one build I made that I posted on another thread earlier, which kind of reflects everything I look for when making a build. So far I’ve identified over 50 pretty unique builds that seem good and I’m sure there are 50 more I haven’t yet explored.