I love tall men. I think that height is highly attractive and that works for me because I'm on the shorter end for women. However, not all women are 5 feet 4 inches tall and don't have as much wiggle room when it comes to fiddling around with their height. One of my girlfriends is 5'9" and is all legs. (Now long legs are always good!) Aside from the fact that she has a hard time finding jeans that are long enough, sometimes she just doesn't want to be tall. The question of how to look shorter is a bit more difficult than that of how to look taller, but rest assured, there are a few eye-deceiving methods.
If you don't want to look tall then don't draw attention to your height. Don't wear super-high shoes, for instance, since they accentuate your height. Another effective way to "reduce" your height is to wear jeans (usually some form of a boot-cut style) with really flat shoes. You'll find that you look shorter when you cut the visual line of your leg off like that. Jeans with either flip flops, flats, or another shoe of the same type is very effective in making you appear shorter. You can also wear longer tops to cut off the lower half of your body, but I don't know how effective that would be given that your torso would then be elongated.
Honestly, there aren't too many options for making yourself look shorter. Perhaps the best way to handle this situation is to build your confidence. A lot of this is mental rather than physical—it's all in the attitude. If you slouch, regardless of whether you're tall or short, it looks sloppy and emits a negative feel. Rule one: don't slouch! Walk with poise and self-assurance, letting everyone know through your posture that you know who you are and what you want. You don't have to emphasize your height if you don't want to, but you don't need to hide it either.
Remember: height isn't bad. It can be slimming and many people find it attractive. Sometimes you just can't do much with being tall—it's one of those things you can't do much about, so instead of doing something about it, do something with it! Even though your height may be the first thing people notice, you have the power to make it so it's not the last thing they notice.