1. Angst does not always equal good drama. Do not kill/maim/torture a character just for effect. Writing a tearjerker just because you want to manipulate the emotions of your readers is not a sign of depth or skill. Keeping the scale and intensity of your stories closer to reality than Opera, means that the genuine emotion you provoke in the reader will be all the more powerful for being attained through subtlety and skill rather than cheap theatrics. Readers identify more with a realistic protagonist's plight than they will the Nibelungen.
2. Relative length is in no way proportional to quality. There are startlingly brilliant vignettes in this world, as well as incredibly well-written novels. Just because something is long does not mean it is automatically good. And anything under 1000 words had damn well better be 1000 incredibly well-choosen words. Quality all comes down to talent and skill. And while the skills can be taught, and honed, God hands out the talent.
3. Show, don't tell.
4. If a character has never referred to another character by a pet name in canon, then it is not always very likely that he or she would start now, even if they have entered into a romantic relationship. Keep your character's traits in mind when you decide to write this into a story—it can be a bit of a stretch for your reader, otherwise, and undermine the integrity of the story you are trying to tell.
5. Don't set out to write a series from the get-go. Write a self-contained, stand-alone story, and if, down the road, you write a sequel, so be it. If you are determined to write a trilogy, then plot accordingly, and keep each of the individual segments self-contained, with their own conflicts and plots that are identified and resolved by the end of each segment. Carrying sub-plots over from one to the next is fine, but ending in the "middle" of a story on a cliff-hanger is ill-advised. It's a cheap, manipulative device that worked great for Dickens' publishers in the 19th century and the Republic serials of the 1930s to keep those nickels coming in every week-end, but it doesn't always translate well in short stories, novellas, and novels. Likewise, don't advertise segments of a series if they have not yet been written.
6. Try to avoid including popular 20th century music in a story unless it's extremely clever and original. Yes, there are exceptions to every rule. But those exceptions are rare. Unless you've got a really solid thematic reason, or clever new way of using this old cliché, steer clear.
As with all maxims, there are exceptions. Authors such as Charles de Lint and Steve Brust use traditional folk music to great effect, but usually this is limited to quoting lyrics at key points of the story, and the beginning and end. It's a stylistic choice, and fits well with most of their urban fantasy. There are also several excellent novels and short stories out based on ballads. Tam Lin and Twa Corbies, for example. Which, you will note, are over 300 years old yet still recognised today. Always keep this in mind when choosing music in Trek fiction. Staying power makes all the difference. What will really be a classic 300 years from now?
Also, there is a difference between basing a story off a song, and using a song in a story. For example, there would have to be a phenomenally good reason for anyone in the Trek universe to be familiar with late 20th century pop music. While Tom Paris may have a great affection for the period, he is the exception in the Trek universe, and even that varies. To date, Tom has been primarily interested in the 1930s through the 1960s. I'd say it's stretching it to have him listening to anything more modern than the Beatles, perhaps. Bubblegum pop from the 80s and 90s is definitely becoming a cliché in fanfic. Gilbert and Sullivan musicals, however, seem to have become in in-joke among Trek writers, so who knows...
If you can make it work, more power to you. Just keep in mind that it has become a cliché, and writing one that works is often more difficult than people realise sometimes when they start out. Top: if you really feel a particular song relates to the characters, then try quoting the song lyrics at the end of the story, rather than referencing it at any time in the story itself. If the story can stand on its own without prior knowledge of the song upon which it is based, then you may not need the song itself.
7. Stories should have a plot, even if it's something as simple in structure as "Tom Paris mulls over his situation, and comes to a decision." or "Chakotay kidnaps Janeway for three hours in the holodeck to explain to her that endangering her life and her crew is not good leadership tactics. Then, they sleep together. A lot." That plot should having rising action, a climax, and then falling action. Even if you are writing a character-driven vignette, you still need some kind of structure. Otherwise, what you have written is a story fragment, or scene, but not a story. Even so-called "Plot? What Plot" vignettes have a structure of some kind.
8. Spelling counts.
9. Grammar counts even more.
10. If you research your topic (be it researching the Trek universe socio-political climates during a specific period of UFP history, or Iowa in the 1950s) your story will be the better for it. Treat SF like a period piece—the same as any historical fiction. Whether it's a western, or a Trek story, your job as an author is to create a solid landscape for your reader.
11. Once you set up your universe's rules, stick to them.
12. If you're going to write time travel, make sure you understand time travel. Otherwise, your readers will never understand time travel. For example, know the difference between a causality loop and a working paradox. Examine your favourite time travel stories, and study how they work (or don't work, as the case may be).
13. Don't rush to finish a story just to have it out by a certain date, or to be the "first" to have a particular type of story out. Give your story the time and attention it needs.
14. Don't start publishing a story serially unless it is finished. Not only do you rob yourself of the opportunity to revise and edit earlier sections based on later ones, you rob your readers of a potentially tighter and better story. Also, if you don't know where you're going, it shows. While having a deadline can keep you writing continually—which is a good thing—no one wins in a situation where the author is simply holding court, posting a story piecemeal simply for the purpose of collecting "we want more!" feedback along the way.
15. Just because a story gets good feedback does not mean you are obligated to write a sequel. Although it is very tempting to continue a story because you enjoyed the attention and want more of it, stories should be written because the idea demands you write. Stories that matter have a beginning and an ending, and prolonging a story simply for the sake of satisfying your audience's need for "more" can result in a rambling, poorly plotted story that loses its impact the longer it drags on. As stated above, and many times throughout this FAQ: put the quality of the work above your own ego. The work itself is paramount.
16. Read a story aloud for flow, and to polish dialogue that may be awkward and unwieldy. Reading aloud is also a great way to spot typos and errors that you may unconsciously skip over when reading.
17. Don't be afraid to step away from a piece for a while, and then come back to attack it with a fresh perspective. This is especially important if you have been working on a piece for a very long time, and are feeling like you can no longer tell up from down in terms of pacing and quality, because you're too close to the work to be objective. In the same vein, go back and re-edit and rewrite sections of past work after six months or a year—just because a story is archived somewhere, that does not mean that you can't improve it over time.
18. Dialogue is crucial, and being able to capture the "voice" of a character can be very difficult. Each character has specific speech patterns, sensibilities, and behaviours. Spend time watching your favourite episodes and pay close attention to what the characters say, how and when. While having an ear for dialogue is a talent that can't always be learned, mimicry is a skill that can be attained through hard work, observation, and at the very least, stealing bits of dialogue from the episodes themselves. Read through your dialogue, and ask yourself, "Is this really something [so and so] would say?" Pay particular attention to word choice and colloquialisms.
19. If a story gets stalled, and is simply not working, it's okay to shelve it. Not every idea yields a readable story, and sometimes, no matter how much hard work you've put into it, it simply won't pan out. Don't be discouraged—just try a different idea, or step back for a while. And keep all your story fragments. You never know when you might find a way to work them into a new piece.
20. Keep a notebook handy to write down snippets of dialogue or ideas as they come to you. Whether you're in class, on the bus, at work, or home in bed, you never know when inspiration will strike.