Take an accurate assessment of your personal style at the moment. Take a long hard look at yourself in the mirror and decide whether you are pleased with your current fashion statements, hair and accessories. Decide what about you needs a style pick me up and do some research on what you find stylish.
Flip through magazines and pour through favorite movies to see what kind of clothing styles and people stick out to you as uniquely stylish. Pinpoint exactly what it is about that person that you find to be stylish, even if it's something you can't pinpoint. The French call it that "Je ne sais pas" (or that "I don't know what").
Notice what it is about the person's style that sticks out as different. Perhaps it's his hairstyle or the way she combines colors or textures. Usually this kind of unique presentation is a representation of personality, clothing and style communicates psychological preferences or interests. Try to inhabit a mood through your style that could possible change daily.
Go shopping for a few new outfits with the notion of shopping for a mood on your mind. Think about what moods you are most often in and inhabit them with your clothing choices. Make a statement about yourself using your clothing and accessories. If you are a down to earth person with little emphasis on style, express your groundedness through earth tones, or earth-friendly fabrics or jewelry.
Pay special attention to your accessories. They often make a person's style stick out. Choose pieces that speak to you. If you are a man, try finding a leather bracelet or even just a ring that reflects your personality. Be courageous enough to be yourself, no matter how divergent it may be from a current trend.
Pick a period in time to inhabit with your clothing. Perhaps you are a fan of 1920s gangster movies or film noir classics from the 1950s. Find pieces with a modern flare that reflect your interest in these time periods.