When it comes to jewelry, I tend to like to keep it simple. For example, last time we went, we spotted this simple gorgeous necklace on a girl and we loved it. Hair down, simple earrings focuses the attention specifically towards the necklace. I love the incongruent shapes and the pearly white color of the necklace because that means it matches with everything.
If you have messy hair that night (like I have on most nights, because there really is no point washing hair before hand to go to a dark club where no one can see your hair and it'll only get smelly and sweaty at the end of the night anyway) I love to pull it back into a fun high messy pony tail (try teasing hair by backcombing) with long dangly earrings like the ones I have above. It frames your face, looks great in pictures and looks fun dancing around while your doing your stuff. 
As for bags, I like to keep it small and on the shoulder, like these Dior and Vuitton ones above of Harrods Girl and mine (yes we took this pic especially for you!). These are just perfect. I can just keep it on my shoulders all night while I'm dancing and not have to worry about someone just "picking" it up in the crowded dark room. Plus, it hold all the essentials: lipgloss, touch up powder, camera, our mobile phone, ID and enough cash for a drink and a cab ride home. 
And lastly, shoes. Generally it should be high heeled (or at least high), strappy (or pointy) and just sexy. But I say its an extra bonus if you can actually walk comortably in those shoes, because after all, you are going to be in them all night! Those gold pointy shoes familiar to anyone? 
