Most Tailoring Patterns do not require you to be in or near a special place or device to create potions. As long as you have all the required materials in your inventory, you can stitch the item anywhere. However, there are several Tailoring Patterns above skill level 300 (such as the 
[Bolt of Imbued Netherweave] which require the Tailor to stand near a Mana Loom.
Mana Looms can be found in:
- Shattrath City : In the Lower City for Burning Crusade players (positioned in between two of the Tailoring Specialist trainers).