Common methods of power leveling include doing only those quests which are most efficient in terms of experience over time, and analyzing the quests in a given zone so as to do them in the most efficient order possible. Remember, the idea of power leveling is speed and efficiency--you may wish to obtain an addon that will show you how much experience per hour you are gaining to test your techniques. Additionally, ensure your character's talent build is crafted for maximum endurance. You want as little downtime (walking, drinking, eating, crafting, typing, etc.) as possible.
Obtain your heirloom rings. Ghost Pirate Rings can be obtained via Shipyard missions. You can equip one ring from this category. A Dread Pirate Ring can be obtained via placing at least second in the weekly Stranglethorn Fishing Extravaganza, which on many realms is a very competitive event. Note that to obtain the Ghost Pirate Rings, you will need a max level character with a garrison of at least level 3. You you will also have to develop your Shipyard to the appropriate level to receive the mission. Your other heirloom gear will still give you a big boost if you choose not to go for these.
Drustvar is far and away the hardest Alliance zone, which is exactly why you want to do it first. If you have legendary items, they’ll still be usable, and if you don’t, this zone will still be easier early on than it will be later. Drustvar is also extremely fast and will let you jump out ahead of your competition in other zones, which means fewer players around to take your quest objectives.