WvW Points: How to spend traits usefully

First, some things to note:

• WvW points rarely get refunded, once you use them they will be forever spent!
  
• WvW points can be spent differently among each character, spend them properly!
  
• Within WvW there are several different ways you may support our team: with the zerg, scouting, and roaming.
  

Following the zerg
Most people in this group are warriors, guardians, necros, eles, mesmers.  You specialize in surviving while bringing down heavy dps (mesmers are used for their utility and support).  While in the zerg, you will spend your points more on using and gathering supply or supportive seige.

• Build Master - Spend 1 or 2 ranks in this line to build seige faster.
  
• Supply Master - Spend 4 or 5 ranks in this line to gather supply faster.
  
• Repair Master - Same as Build Master, except with repairing.
  
• Flame Ram Mastery - Spending 2 or 3 ranks into this trait helps whenever other people in the zerg are not mastery.
  
• Catapult Mastery - Spending 4 or 5 ranks here may be beneficial depending on the commander you are following.
  

Scouting
Classes do not matter for this, you stay within the given tower/keep/castle and pass important info onto team or map chat.  Very important role, and potentially as rewarding as being in the zerg.  If you see a zerg, you tell numbers in the zerg, whether seige is down or not, and any info that may be needed.  You will be refreshing seige (just interact and use seige every so often, so the timer on it refreshes to 1hr), and upgrading the tower/keep/castle (potentially nearby camps as well).

• Trebuchet Mastery - spend 2 ranks and always place a trebuchet to hit the gate (be smart where you place it, you don't want other people to be able to hit it).  When a zerg comes to the door, fire a cow at it and the zerg cannot place seige in front of the gate due to you draining their supply.  Alternate with the cow and the regular shot and you'll drive them away or get a lot of bags at your feet.
  
• Arrow Cart Mastery - Spend 4 or 5 ranks into this and you could be swimming in loot when a zerg comes by.  *Do not confront a single person while on an arrow cart, the cooldown is not worth it.  Instead, focus into a zerg or onto downed players and you'll get lots of loot.
  

Roamers
These are high dps/burst dmg players.  Generally are thieves, warriors, mesmers, engineers, elementalists.  They take camps, kill yaks, capture points and basically solo things.  They should use map chat to tell where an enemy zerg is if they see them, and focus on more 1v1 confrontations.  WvW points can be as scattered as they want, they rarely use them anyway.


Other things to spend points in
These are for the higher ranks, who don't need to be as stingy with spending points.  They have hundreds of points to spend and probably don't need this guide due to the amount of time they have spent in WvW to get the points.

• Defense Against Guards - A full 10 ranks spent in this trait gives you +50 vitality for each guard you kill.  This means you can get +250 vitality from taking a camp and a tower.  Very useful in staying alive within zerg vs zerg fights (fairly good for players with low hp pools like mesmers and elementalists)
  
• Guard Killer - Works similarly as Defense Against Guards, except with +20 power and +20 condition damage instead of vitality.  Not as useful in fights as Defense Against Guards, as surviving is more important.
  
• Seige Bunker - 1 or 2 ranks into this line is fairly helpful in surviving.
  
• Supply Capacity - Nice to have, but really expensive and not worth the gain.
  

Source: http://www.reddit.com/r/Guildwars2/comments/1lqaz2/guide_with_the_refund_coming_heres_a/

Well I realized recently the best way to spend points while in zerg was what Tia said... Too bad I had spend most of mine for defense/attack vs. guards.

WvW is pissing me off a bit this rotation as JQ and TC are really taking the piss... And it's not the first time, I don't know why Anet isn't doing anything. I get it it's kind of "smart" to ally with another server but come on...

Running zerg or even in small groups of 5-10 players I find supply mastery, build mastery, and flame ram mastery come in very handy on my guardian. AC mastery and treb mastery are a must for a toon that is going to work as a scout or be used primarily to defend keeps.

With the queues the way they are though, and the current tourney, having different toons specialize is difficult. The shared ranks are super nice though.