I used fully upgraded and enchanted heirlooms; missing only the fishing ring. Leveling from 1-20 took ~3 hours, at which point I immediately turned on War Mode for the duration. I rarely encountered enemy players, and when I did they almost always left me alone. But the few times I did get ganked, the total cost in time was insignificant. Maybe a total of 5 deaths from ganks in the entire 40 hours. 

EXCEPTION: If you have Mining and only use Jewelcrafting to craft stone statues (for additional in-combat healing), then this may be a useful tradeskill. However, like Engineering above, it should not be a leveling focus and should only be used to assist with power leveling. Doing any more than this will become costly and should not be undertaken during the power-leveling process.

As the gold price of a $20 token falls, more people with gold are willing to convert it into tokens, and fewer people with money are willing to buy gold at that rate. As the gold price rises, the value of the token begins to exceed the value of the time spent accumulating the gold for some market participants and they stop selling their gold. Meanwhile, other people with cash are enticed to enter the market because of the high amount of gold they can get for their tokens.
With 8.0, Blizzard introduced World of Warcraft’s second ever stat squish — where all the numbers in the game are lowered across the board for clarity. While it may make the game easier to read, it has caused some serious in-game problems. Since the patch, Blizzard has been throwing out hotfixes each day, fixing things that the stat squish either forgot to alter or simply broke.
At 96 the standard wisdom is to immediately drop what you're doing and proceed to Spires of Arak and do the quests to unlock the Inn, granting a further 20% experience bonus while in that zone. You'll want to do that eventually anyway, but I'm not sure it outweighs the quest experience from Gorgrond. However, if you decided to go to Spires immediately at 96, restrict yourself only to bonus objectives and again leave Treasures until you're 100+. Make certain that when you being the quests to unlock the inn, you speak with the quest NPC to also learn Archaeology, since it's required to collect several of the treasures in Spires.
I made one for my guildies but its for the Horde leveling process. One tip that goes for both factions is that you dont need to do all 3 zones to hit 120. I did like 1 and than three quarters of another. But once your 120 you need friendly with all 3 of your factions new reps to unlock world quests so make sure you hit at least friendly with all 3 while your leveling.