In my general approach to threesome stories I find that planning is crucial. I have never been able to write one off the top of my head without it getting twisted and confusing. The basic thing is to keep movements simple, it's easier to feature two of the three at a time, rather than try to involve three different moving characters.
You should go ahead of yourself and write out exactly what you want from each scene and list what each character is doing at that given moment, if they are doing nothing then you obviously don't write that down.
Hope I've been of some assistance, I'm still new around here.
Back to writing ....
Fly
P.S. I'm actually working on a threesome story at the moment which grows to a fourway romp with a fifth chracter entering the fray. I don't recommend it to anyone because it is very difficult to write about five people in motion at the same time, and keep the story brief and flowing .....
Very good advice Fly. I'll just add that in addition to keeping body parts straight, keep it real. Make sure that the mechanics of the actions are believable. Picture what they are doing in your head and see if it is physically, comfortably possible. If you have them bending backward and rolled up like pretzels it won't sound very believeable.
I've written a couple of 3 some stories and keeping everyone real is a big key.
Good luck,
Wicked makes a great point, and probably the best one, make sure every characters positioning and motions are "real." It happens to us all when we get stuck into a story and start moving people here and there.
From experience I sometimes overuse one character over others which means one person is doing the bulk of the work while the other two are secondary. It can become really distracting for a reader unless you are setting up the story to be one persons experience ...
read and re-read and re-re-read again to figure out if your own stuff makes sense to you! If you find yourself confused about what your own characters are doing, then, well my dear, there's a problem.
For any story, I'd say just remember to keep it as real as possible (cause I like real stories) and have fun with it. Don't describe things play by play "she licked his dick and then she licked his balls and then his dick got hard and then he came all over her 78XXX size tits"
I find my best ideas are when I'm feeling horny and thinking about masturbating. Get on the keyboard and type like fury, leave yourself alone and yuo may be surprised at what turns out.