Shadows of Eberron
This background reflects those who have strong ties with their respective Dragonmarked house. Nobles are those who have had the best education, the best training and all of the benefits of their house made available to them. You manifested your dragonmark at an early age and have known since then that you are destined for greatness within your house.
But that is all in the past. Now you are adventuring. Have you somehow fallen out of favor with your house and are seeking to atone? Is this path of adventuring your way of proving yourself worthy of your greatness and status within the house? Are you trailblazing a new technology that will bring further financial success to your house (or to yourself)?
Dragonmark feat at 1st level. This is in addition to the feat humans get at first level. This allows all races the ability of being dragonmarked at 1st level.
Favored in house: You are kind of a big deal. Your house has invested a lot into you and they want you to succeed. You have political currency that you can cash in with your house for small favors (and sometimes large favors) in fields that your house can affect. Examples would be arranging airship travel for the party if you were a Lyrandar heir, or free healing at a Jorasco house, or access to skilled trackers from house tharask. DM sets the DC and higher DC’s increase the time in between favors.
Specialized implements: Dragonmarks are not just about the spell like ability they grant. There are many items created from dragonshards that are fueled by the magic of that mark. As a noble, you would have a specialized item that helps you perform the functions of the guild you were once associated with. Confer with the GM around what that item could be and what powers would it have. All ideas are welcome.