What are the best professions for Templar?
The main Templar’s role is to defend, to tank. Therefore your professions should ease you that. Your main defense is your plate and your shield. So natural choice here is Armorsmithing. Then, if you have time and money, you can choose one, or both of following: Alchemy and Cooking. Alchemy gives you cheap access to best healing and support potions, and you will need them often (you’re tough but you put yourself in most dangerous role out there). Cooking gives you access to food, that also provides more hp, protection, etc. It’s always better to make all needed items by yourself, than pay for them a lot.
