Assuming I know the characters and the fandom, I don't tend to treat requests that just ask for fluff or characters hanging out or post-canon stories in canons where all the problems are resolved. While I understand why someone would want their holiday surprise to be something simple and happy, and would write that if it were my assignment, for treats I'm more inspired by prompts that add some sort of friction or conflict, or otherwise inspire me to elaborate on part of the character we only got hints of in canon.