Tulipa said:
Agreed.
You don't need a gimmick or a twist ending, which can seem pretty crappy but at the same time it has to have a "point", something that the reader can take away. No matter how insignificant, we need to be rewarded for reading it.
Listen to Tulipa; she knows what she's talking about (I'd like to think I do too, but I'm not going to say it outright). Go for smart dialogue, interesting characters and underlying themes to the work before you start looking at gimmicks. If your readers can't remember anything about your work, chances are your markers will reward you accordingly.
You're going to go through draft after draft before you even get to the final idea (and even then, you'll be looking at multiple re-writes). For every story idea that I've managed to translate into a finished product, there have been half a dozen that have fallen by the wayside owing to various reasons. Plots don't work, themes can't be incorporated into the story and still come in under the word limit, writer's block means pieces won't get finished, etc. But if there's one mortal sin that you absolutely
cannot commit, it's deliberately writing to the word limit. Once that 8000-word mark (or however many it is) comes up, you'll start to wrap things up, and the problem is that your ending falls well short of the standard you established with the rest of the work. Sit down and write, and keep writing
until you finish the story. If you go over the word limit, you can cut it down to size or do a re-write of parts. After all, that's the virtue of editing. Make sure you get someone to proof-read it before you do so, though. On that note, don't go to an immediate family member, I find they have a tendency not to offer constructive criticisms properly and may lie about it outright to stop you from feeling as if you've wasted your time.