For those who are unfamiliar with the concept, your Dear Secret Mutant letter will be a post hosted at your blogging platform of choice (LJ, DW, tumblr, whatever other hip thing the kids are using these days) that generally lays out what you like to see in stories, what you don't like, some additional ideas you have, etc. Some writers/artists find an exact prompt easier to create for than a more general one, while others feel the opposite way, so it's just another way of making it clear what you like and giving your gifter some options. They're also helpful if you know you're going to be busy or out of town during when gifts are posted, so your gifter knows not to expect a thank you comment until you return.
The best way to get an idea of what to include in your letter is to browse others. Here is a link to the 'Dear Secret Mutant' post for last year's exchange. Feel free to browse some of those to get a feel for how letters are composed.
"Dear Secret Mutant" letters are totally optional. If you feel like your sign-up stands on its own, don't feel obligated to write one!
If you do decide to write a letter, please leave it in the comments on this post in the following format:
Link to letter:
NOTE: Sometimes LJ marks legit comments on a high-traffic post such as this one as "suspicious." I'm going through a few times a day and approving all the suspicious comments, so if your comment doesn't come through immediately, never fear--I will get to it the next time I check!
(If it's been a couple days and it's still not showing up, shoot me a comment/email/ask on tumblr and I'll see what's up.)
If you have any additional questions, feel free to ask!