RECEPTIONIST = GATEKEEPER
My best advise? You are the gatekeeper. You are most prospective guests deciding factor on if they are going to bring their business to you or not. You are not just a receptionist. From the way you answer the phone to the way your greet your guest, YOU ARE THE FIRST IMPRESSION, and as we all know...you only get one first impression.
To be frank, it is very simple and easy and takes no extra time out of your day to be courteous and nice. Laziness is the only reason for not giving out a warm smile and a sincere "Hello."
Be aware...are you the reason business is not beating down your doors?
Take the time, Gatekeeper. You are the key to a successful business!