This info can become very valuable in the right hands, some you might know, some might help you out.
Potions are often overlooked with oil/stone/crystals.
They can offer up to 10% extra damage and defense making them great for tough fractals or farming same mobs.
Only downside is you only get buff vs one type of mob.
I Recommend gettting the highest tier thats below 1s so you dont needlessly blow your money on them.
You can get 10% extra damage at night in a lot of places with http://www.gw2db.com/items/70896-superior-sigil-s-of-the-night
The places that are considered night are:
...Dungeons: AC, TA, SE, COF, COE
...Fractals: Swamp, Snow, Dredge, Grawl, Maw
...WvW: Day/Night cycle. AC weapon Skin glow= night.
Karma Chart
http://wiki.guildwars2.com/wiki/Fractal_Karma_Reward_Table
So to get max karma, do fractals 9 levels below your reward level
Location: http://wiki.guildwars2.com/wiki/Cloth_Aquabreather
*TIP* To get full 6th rune set bonus underwater you must mimic your rune on helmet slot, because underwater the helmet disapears and aquabreather takes its place
To find back item on tp, search for Spineguard.
Also, its not under any specific section so just straight search for it.