Summarize this article:

Its always important to greet your clients in a friendly way. Even if you continue what you are doing before helping them, its important to greet them so that they feel acknowledged and know that you will help them in a moment. Some greetings are "Hi! Welcome to [Business name]" or "Good morning! If you'll have a seat, I will be with you in just a moment!" Be respectful. Treat everyone like they are the most important person that has walked into the office that day. This is your job- nobody cares about how you got stuck in traffic this morning, how you ruined your brand new purse, or even how you lost your favorite CD. Leave personal matters at home. (Even if you don't respect their message or the way they convey it- fake it) Overall, make sure the person is totally relaxed and happy to talk to you. You are representing a business, thus you should dress the part. Invest in some business casual clothes. Alternatively, if you are a receptionist at a specific sort of store (such as a clothing store) you may consider dressing the part by buying some of the store's clothing and wearing them. Tend to the conservative, unless you work somewhere where fashion, trendiness, or other factors are pushed to the forefront. Check to see if your business has a specific dress code. Your business may be fine with casual dress, just remember that you should never dress too casually (sweats should be banned from the workplace.)
Have a greeting ready. Be courteous. Dress to impress.