Most stories on here would have to deal with a introductory paragraph where any new character introduced needs a description, but someone reading a fanfic would already be familiar with the character. Detailed descriptions can help set the mood of course, but I'm wondering where to draw the line between 'this is sexy' and 'this is irrelevant, I know how this character looks'. Any advice is apreceated.
In general, I think it's fairly author/style dependant how much time you spend on descriptions. I personally like to give a brief overview of what a character looks like, focusing on what I feel is the most important details (for example, maybe the character has a tattoo which is relevant to them). I may then expand on that during a sex scene if necessary. That said, some might find my style light on the descriptive side. It may also be dependant on the situation. A person may analyze someone more deeply if they are interviewing them for a job rather than just checking them out at a party. Considering Fanfics feature known characters, I'd steer towards being light on descriptions, as people would be familiar with the character. Despite the fact they are known, character descriptions are most likely a useful tool (DISCLAIMER: I haven't written any fanfic), you may have to differentiate between certain continuities (For example, a character in the Marvel Comics may look different in the Marvel live action movies). Character descriptions may also be important if writing from a first-person perspective. In the end, I'd say so long it doesn't bog down the pacing too much, any description is fine. The only thing that I really dislike is when people use terms such as 'he's five foot eleven' or 'she has 34D breasts'. To me it reads more like a police line up (which to be fair could be fine if the context of the story is a police line up) rather than a person looking at another person.
Keep things vague (eg hair color, curvy, thinly built) and focus on key details that others might see in them like a character trait or better yet a body part that emulates their character (eg a preppy teen having upturned boobs). I hate it when people list every detail of the characters as if i will somehow remember them all as im reading the story. With height, say you have a 6'8 character. Dont list him as saying he was very tall but describe how he towers or casts shadows over others or makes others feel small and insignificant as they interact with him.
