Writing Queer Relationships, Part II

The other problem queer couples in Fictionland face, besides all the Fred Phelps clones who seem to have fallen out of the time vortex into their fantasy world/historical setting/future spaceship is the Bad Slashfic Syndrome. The first symptom is an incessant need to mess up established characterisation to get your two queer characters together. This is followed by the shoehorning of said characters into gender and dominance roles (usually a submissive femme and masculine dominant). Finally, bad sex scenes set in. 
It seems self-evident that non-hetero people are, well, people, complete with unique personalities and interests and backstories which have little or nothing to do with their orientation*. More importantly, just because a relationship involves two people with the same gender identity and/or chromosome pairing, it doesn't mean the usual rules of partner selection don't apply-- people bond over shared interests and experiences, and mutual attraction. One's pool of potential partners might be smaller, but that doesn't mean that any two people with a compatible orientation will be a good pair. 
Which brings us to the 'faux fanfic' problem. In slash fanfic, the driving force is creating scenes where the two characters get to screwin'. This can mean messing with characterisation a bit so that the hot folks end up as a hot couple. In an original story, however, you're writing the characters from scratch (I hope!), so you can make the characters as good (or awful) a match as you want. If your end goal is to write a romantic story with the two leads getting together, make sure you write their compatible traits into their original characterisation. 
This messing up of established characterisation can also be the product of trying to shove the characters into an established set of binary gender roles. A couple does not need to have a 'masculine' and a 'feminine' member**, or a dominant and a submissive member. Any combination of gender expressions and power relations is possible, so just go with what's appropriate to your characters. 
Finally, if you're going to write the sex scenes, please research how same-sex couples get it on (and seriously, if you can't look up the requisite positions, etc. without having a giggling breakdown, you are not in any shape to write a sex scene). Try a queer sex-advice book or website-- porn is probably the worst way to do your research, at least as far as looking up how people bone in real life. There's no faster way to ruin the mood and the reader's suspension of disbelief than to have some impossible sex positions or improbable anatomy.  
*In all fairness, I once lived with someone whose orientation was her entire identity-- her only interests were (as far as I could tell) gay rights, naked women, and feeling ambiguously persecuted.**Usually using modern Western gender roles as a template