The freeing thing about current night club style is that there is no overarching theme that must be met. This isn't the days of Travolta and disco fever where you wouldn't be welcome in the doors if you weren't wearing the somewhat strict uniform of the time. For now, there are a lot of options when it comes to what you choose to wear. But those options don't extend to include sweat pants and a ratty T-shirt. If you would think twice about wearing an ensemble to Wal-Mart, you definitely shouldn't wear it out to a night club.
Assess the Situation
Since there are no hard and fast rules that can apply to every situation, you have to assess it yourself. The first step in doing so is knowing a bit about the night club you're going to attend. Is it a laid back, casual type of place or is it a fancier establishment where they will pull a sport coat out of the closet if you show up without one? Even without knowing the particulars, however, there are some general tips you should follow if you want to stand out in a good way. Stick with darker, muted colors unless you really know what you're doing. Accessories like watches and cuff links make the grade. Ball caps don't.
Don't Embarrass Yourself
It's easy to embarrass yourself if you try to bring street fashion into an upscale night club. No matter how many celebrities you see doing it, sunglasses should never be worn indoors, especially not to this type of establishment. You are going to be seen as a poseur, which is the last thing you need when trying to make a good impression. Shorts are an absolute no-no as well, regardless of how comfortable you may feel in them.