Right, for those writing a marauders fic:
The Marauders were not straight british lads and they would never refer to each other by their Marauder names. In fact, if you depict the marauders in any kind of heterosexual bro-fic, you ought to be dragged out and stoned.
Instead, they were all effeminate japanese poofs. Especially Remus and Sirius, who are in love with each other and refer to each other as 'Siri-Chan' and 'Remi-Chan'. 'Moonie-chan' is also acceptable where Remus is concerned. (Moony must be spelled with 'ie', not 'y' or it just ain't cutesie enough)
In instances where Remus and Sirius have no interest in each other, one of them is required to be in love with Snape. All canonical loathing is to be thrown out of the window. Sirius and Snape really just fight because they like each other.
If you feel like one of them can be straight after all, Remus can be in love with Lily.
If the Marauders fic you are writing is post-Azkaban:
Remus is not ill and exhausted with shadowed eyes and a hoarse voice.
Sirius is not gaunt and filthy with matted hair and sunken eyes. Even in stories where it is expressly stated that he is fresh from a long stay out of doors on the run and has had no access to basic necessities.
Instead they are both fit and healthy and gorgeous. Their bodies are toned and smooth and youthful. Sirius' hair is long and flowing and Remus' greys are forgotten.
In all marauder fics remus must have gorgeous, luscious, amber eyes. ALWAYS AMBER! not brown, AMBER!
Even in adulthood Snape is a viable option as a lover for either Remus or Sirius.
Snape is not greasy, or hook-nosed, or bitter, or even a ginormous snide git. He is as beautiful as the aforementioned post-Azkaban Sirius and not nearly the jerk Sirius remembers him to be.
Remember, no matter which of the above options you choose, the fluffier the story, the better.
Also, if the werewolf transformation is addressed, it must be described using lines lifted directly from 'Being Human'
[[ I know why this area really hasn't been addressed. because there are too many Remus/Sirius shippers. Because after all, one brotherly embrace after over a decade of separation and mistrust makes the relationship 'practically canon' and two books worth of Remus and Tonks in an actual relationship isn't worth diddly. rolleyes ]]