I think the most important, and fun part if you ask me, is to experiment. Do not be afraid to re trait, change armor, jewels, weapons, upgrades ( sigil's and ruins). You may find some shocking results with simple changes, and you may find certain builds compliment one group (ala WvW or Dungeon) and another build is far better suited for PVE or general group runs. It is cheap enough to re-trait to make it fun to try, and if you put any time into gathering stuff or crafting you are sure to have a whole host of weapons, armor and upgrades to mess with.
Have fun and do not be afraid to go against "the internet experts" as a lot of it may really hinge on your group if you have a regular one. It a game after all enjoy it and play it.
I agree with this.
Plus it comes down to PERSONAL preference. For example, with a build I used to run my auras give me fury, swiftness and protection for a nice duration as well. When I run with my guild, I pick a master water trait that also gives my allies (up to 5...so my the guildies I'm in a WvW group with) auras as well with all those benefits. Mkes my group that much better with swiftness, 20% increase in crit chance and 33% reduction to damage taken...and I get quite a few auras.
But when I run with pugs...I worry about my own safety more and worry about others safety less...so I change that trait for one that removes conditions when I apply any heal. Benefits me more, others less. And that just for one trait.
There is no "best" because that varies with what you do, who you're doing it with, and what your personal preferences are. And yes, I just realized how that could come off very "TWSS".
I don't have a condition build on any of my toons, but they all make use of conditions, theif and ranger especially for bleeds and its a nice extra amount of damage to add to what I am already doing or force people to use skills to remove them. One condition that doesn't do damage (and that I find most annoying in a fight) is blind. Being able to spam blindness onto a foe is pretty awesome and sucks when it happens to you. Blindness can easily removed by just auto attacking and missing, but when its spamed (constantly reapplied) it makes for a real threat to your life. Just thought I'd throw that in there since we were talking about other conditions, enjoy.