Summarize:

Many jobs today allow their employees to dress in what is commonly called "business casual" and involves khakis, slacks or skirts and collared shirts or blouses. However, some offices may require a more formal dress code and working on a construction site would likely have very different requirements. Take note of what people are wearing during your interviews. There's no better way to know what is considered appropriate work attire than to see what employees are currently wearing. Always err on the formal side when starting a new job. It's better to appear to be overdressed than too casual. While the dress code in your new office may be a little relaxed, it's best to begin your first day with a fairly conservative appearance. Once you get to know the environment, you may be able to relax on some facets of office attire and presentation, but wait until you're sure. Stick to relatively conservative hair styles, makeup, and jewelry until you know the office culture. Take cues from your coworkers on what the acceptable limits of office appearances are. Always check the employee handbook for rules about employee appearance. There are many kinds of professional footwear on the market and you should make sure to match your shoes to the work you will be doing. Your shoes should appear professional and in keeping with the style of dress that is expected in the workplace (like wearing dress shoes with a suit or boots with work pants on a construction site). Make sure your shoes are comfortable, especially if you will be on your feet a lot. While the comfort of your shoes won't directly create an impression, focusing on how bad your feet hurt will make it difficult to focus on other more important things. Check the employee handbook to make sure there are no limitations on things like heel height for women or a requirement to wear non-skid shoes in certain environments. Now that your outfit and shoes are perfect, you need to make sure your grooming matches. Personal hygiene can have a dramatic effect on first impressions and no outfit can compensate for bad body odor. Get a fresh haircut before your first day on a new job. Make sure to shower and wear deodorant. Trim your fingernails and ensure you don't wear makeup or nail polish that is inappropriate for a professional environment.
Choose your outfit based on the job and environment. Start with a conservative appearance. Wear smart shoes. Make sure you are well groomed.