When you have guests to your home, be sure to greet each one personally as they arrive. If you are hosting with an open door, keep yourself near that door and pay attention. The moment a guest arrives, you should take their coat, welcome them in, and offer them a drink. Then, make introductions.
Nothing is more awkward than walking into a party, dumbly clutching your coat, not recognizing a face, and not knowing what to do with yourself. We once walked out of a party because of this very lack of welcome.