first of all, thank you so much for participating in this challenge and offering to gift other people with fanfiction. I hope my prompts inspire you and will challenge you in all the good ways.
Secondly, I wanted to let you know that whatever you write, however you write it, I will enjoy it. There is nothing I enjoy more than creativity – and that means, GO NUTS! Take my prompt and go crazy with it, put your spin on it, throw in something that is essentially you. Don't worry too much about what I like; if you enjoy writing it, I will enjoy reading it. That much I know for sure.
There are, of course, things I love and prefer to read over things I 'just' like to read. As you might have noticed, most of my prompts (and all of my own fanfics) are very heavy on Dean-centered hurt/comfort. What can I say, I simply love hurting that handsome son of a bitch. However, that doesn't mean I wouldn't enjoy some hurt!Sam or something that has nothing to do with hurt/comfort at all. If your story ends up being completely fluffy, that's alright.
On the other hand, there are things I avoid if I can help it. One of them, for some reason or another, is AU fanfiction. I have nothing against what-if scenarios and AUs such as the End!verse, but I have never seen much point in reading (and writing) fics about my favourite characters in completely different settings. Other things I tend to pass are mpreg fics and any form on non-con. I'm not big on de-aged boys and genderswitch, either. However, if your Muse hits you over the head with an idea for an epic AU you could write for my prompts, then you of course can. As I stated above – creativity!
I hope this letter was of use to you, as it was meant to help you. If not, feel free to disregard it and write as your Muse supplies.
Once again, thank you for writing a piece of fanfiction for me – I appreciate it very, very much. I hope you will enjoy writing one of my prompts and won't stress yourself over it too much. We're in this to have fun, after all.