The professional world has definitely become more casual in the past few decades but that does not mean that you should dress as if you are going to a ball game. If you work in a professional environment then you need to make sure that you are dressing appropriate, if for no other reason then that you want to be promoted one day. The general rule is that you should find the highest ranked person in your office, which will probably be dressed very appropriately, and you dress like they are if not better.
Appropriate attire for the workplace has more to do with fit than you would think. You could be wearing an expensive suit but if the fit was wrong then you would look bad. The best advice for any professional person is to befriend a tailor. When you buy pants that are to long, rather than letting them drag on the floor and get torn and dirty, have them hemmed. If the dress that you are wearing is slightly to big and you can see bra rather than just shrugging it off, have the dress taken in.
Keep your makeup and hairstyles to minimum. You could the most appropriately dressed person in the room but if your makeup is caked on no one will be able to look past it. Remember that when people are speaking each other they are staring into each other’s eyes. If your face has so much makeup that you look like a clown, whatever you have to say will probably not be obsorbed. Where neutral tones when you are going to the office. Look polished and put together, not over done. If you play around with different hair styles or colors just make sure they are appropriate. You hair color should be one that is found in nature and the style should not draw attention.