At Level 62 you can pick up the quest Firewing Signets from Magistrix Fyalenn <The Scryers> in the Scryer’s Tier, Shattrath.

Turning in Firewing Signets gives 250 rep.

At Level 64 you can pick up the repeatable quests More Firewing Signets and Single Firewing Signet from Magistrix Fyalenn <The Scryers> to turn in Firewing Signets either individually or in stacks of 10.

Turning in More Firewing Signets gives 250 rep.
Turning in Single Firewing Signet gives 25 rep.

These quests are only available until Honored. Make sure you turn in the Single Firewing Signet quest so you’re just below the threshold for Honored, then turn in 10 Firewing Signets for More Firewing Signets so you’ll be boosted into Honored. For example, you have 5760 Scryer’s rep. Turning in  quests to get 225 rep up to 5985 will allow you to turn in the last 10 signets for the quest More Firewing Signets to plunge you 235 points past honored.

At Level 64 you can pick up the quest Synthesis of Power from Voren'thal the Seer in the Scryer’s Tier, Shattrath.

Turning in Synthesis of Power gives 350 rep in addition to the Arcane Rune needed to purchase the shoulder enchantments from the quartermaster at the bank.

Once you’ve turned in Synthesis of Power the repeatable quest Arcane Tomes becomes available.

Turning in Arcane Tomes gives 350 rep in addition to the Arcane Rune needed to purchase the shoulder enchantments from the quartermaster at the bank.

At Level 68 you can pick up the quest Sunfury Signets from Magistrix Fyalenn <The Scryers> in the Scryer’s Tier, Shattrath.

Turning in Sunfury Signets gives 250 rep.

You must first complete A'dal and then City of Light in order to do the Allegence to the Scryers quest. Completing Allegence to the Scryers gives 3500 rep, which is enough to get all races except the Draenei into Friendly. Blood Elves start at a higher reputation level. Assuming the player starts out at (0/6000) Friendly with the Scryers:

Collect 240 Firewing Signets from grinding mobs or the auction house.
24 turn-ins of Firewing Signets gives 6000 rep.

This brings you into Honored. From Honored you can choose to go one of the following routes alone, or in combination. See below for more detailed info in making your purchase decisions.

Collect 1320 Sunfury Signets from grinding mobs or the auction house.
132 turn-ins of the Sunfury Signets gives 33000 rep.

OR

Collect 95 Arcane Tomes from grinding mobs or the auction house.
95 turn-ins of the Sunfury Signets gives 33250 rep.

39000 rep will take you from (0/6000) Friendly to Exalted.