Traits: Attention-grabbing, totally amazing, special snowflake
Ah, Mary Sue.
Sometimes spirit guides choose us, and sometimes we go to them. Working with the concept of Mary Sue in this way is very much the latter. If you're going to seek out a guide who has the qualities you want to learn, why not start with someone who is, by definition, your idealized self?
Months ago, Deb at Charmed Finishing School wrote:
But I realized that if I wanted to become That Girl, I needed to wear her clothes. I needed to become her. If I wanted to change my set point I needed to do as Gordon suggested and enchant my purse. I needed to step up.
And that's the thing about Mary Sue. Writing a Mary Sue is a small act of rebellion and reclaiming. You're taking back the idea that you don't matter enough to be in your own stories. You're announcing to the world that fuck yes, you are that awesome. You're too good for Harry Potter, Sherlock Holmes and Dean Winchester, and they better not forget it.
Mary Sue is not unlike your Higher Self. She's what you want to be, and engaging her is a good step on the path to getting to that state of alignment with your own Mary Sue.
To start working with her (or Marty Stu), think about what you want to be. Describe yourself the way you want other people to see you. Go ahead and write it down like it's the introduction to a fanfic if you want to; if not, just visualize it. What is she wearing? What is she carrying? What is she doing?
Now think about those traits and figure out how to get there. Start small - if your Mary Sue is a goth who goes out in full regalia, maybe you should start dressing more epically. If she has a business making magical objects, maybe you should take a class on woodworking or jewelrymaking. If she's the kind of hedgewitch who uses bones and home-grown herbs to build her spells, consider getting some smaller potted herbs to start or learning to break down a corpse.
You can learn to be that person who's always cooler than you. Don't just aspire to be that awesome - see your inner Mary Sue, and then start taking steps to become her. Call on her when you need self-confidence, and ask her to help you see yourself as the hero(ine) of your own story.