Create new trial character. (its an option on the top)Select the class you want.Use Garrison hearthstoneSend 10 gold to your mainOpen lockbox for extra weapon transmogs.Now you have a full appearance set of armor learned and ~9 gold for minutes of work.
Teleporting to garrison allows you to roam around the world. Haven't tried entering dungeons though. But I was able to skip the legion introductory quests directly to new dalaran.
Enjoy!
Note: All premade transmog items have a class restriction to the class of that character. Note2: Garrison missions sometimes give gold as reward again. Note3: You cannot do any of the dungeons on trial boosted characters, but you can travel anywhere in the world and you can join guilds and parties. Might be useful for farming old world bosses.Note4: This feature is only available to those who have bought Legion expansion.

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