Straight from the get-go, let me apologize for taking 3 days (omigosh!) to reply to this wonderful introduction of yourself! Thank you for choosing Guild-Air, we hope you enjoy your flight and in case of a crash you're pretty much screwed. Either way, great to have you aboard my friend!
As for your positively interesting question (of which the initiative I adore, by the way), my personal answer would be this:
First of all, How can you be the most succesful roleplayer you can be? That's an easy one, really. Have you ever played a board game? Did you ever see a commercial of it? Did you ever see someone on the losing side in the commercial and *not* laughing?
Writing is like that. It's easy to lose yourself in the feeling of responsibility to cater to the person on the other side of the book. Sometimes you'll feel like you want to write something, but you write something else so the other person can respond better/enjoys the sentence better. Always remember you write, because you chose to. You're not writing for anyone else, you're writing because it makes you happy!
My personal best roleplay I have ever been in is a short-lived one. It was a Dungeons & Dragons game and while it wasn't perfect (far from it), it was the most blissful childish moment in my life. I got to play pretend again as if I were ten years old and had amazing fun in the most magical world a person can think of. If you ever get the chance to play D&D with someone (if you haven't already) I'd surely reccomend it!
Tl:dr. GL HF bruh, welcome to the Guild :3