I think that the gods of the doorway are perhaps one of the most important set of gods in the household. There is of course something to be said for Zeus and Hestia who dwell at the center of the household and are a part of the bounds that hold families together through generations and descendants to their ancestors, but sometimes it is easy to forget about the doorway gods, perhaps because we are so busy with our comings and goings that we sometimes forget to take notice of how important the doorway is. It is all too easy to take a casual attitude especially when many of us have the means to go where we want at any instant. The automobile makes it easy to zip back and forth from the house and therefore we find ourselves in a continual rush in and out of the house many times a day. It is a lot easier to take a breath and relax in the heart of the house and pay respect to Hestia for instance, but also a lot easier to forget about honoring the gods who guard the doorway and boundaries of the household.
Certainly the fact that we have several deities connected specifically to the boundaries and doorways shouldn’t be taken lightly. In fact there is all evidence to suggest that this area was given much serious consideration. Hellenes had several specific gods associated with different areas. For the property boundaries you had Zeus Horios and Apollon Horios. For the entrance you had Apollon Agyieus (of the road) and Apollon Thyraeus (before the entrance/of the door) along with Hermes. Meanwhile, of the door itself you had Artemis and/or Hekate (I personally include them both). Amusingly unlike Hermes and Apollon, these goddesses were associated with the doorway among Romans, whereas for Hekate there is a popular image that was hung inside and for Artemis there have been archaeological finds of nitches just outside the door in which Artemis stood, made from terracotta, with open spaces in her hands that are suspected to have been used to hold small torches. Despite the fact that the Romans don’t honor Apollon and Hermes at the door, I was astounded by just how many gods they had associated with various part of the door, it was nearly mind-boggling! And then there was Janus, the double faced god, who in his practical function associated with the door combined with his solar characteristics was quite reminiscent of the role of Apollon and Hermes at the entrance….which could explain why the domestic function of these gods never took hold in Rome when these gods were adopted by the Romans. Even in India I have recently seen a picture of a house with two phalluses painted just outside to repel evil and bring in good fortune.
Thus we arrive at the importance of the gods at the doorway. More so than anything else they protect the wellbeing of the household. If you consider the household a microcosm of the city it makes sense that whereas the city has gods who protect the welfare of the state, and consider such gods of high importance, so too would the gods of the oikos have gods with such duties. In the case of Apollon, Hermes, Artemis and Hekate we have deities who are by their natures liminal gods and goddesses. Hermes escorts souls to and from the otherworld as he is the journeyman and divine messenger who travels upon the roads from one destination to another, Hekate is a titanide associated with the interlocking of the three primary divisions of the world, and Apollon and Artemis are frequently a part of the wild refuges while also playing a large part in the welfare of the state and as such move back and forth between civilization and wilderness (for which bears out connections to roads, vessels such boats, etc). It is these gods collectively who protect the house and nurture its healthy state of being.
They protect the household, going so far to drive away impurities/pollution, *evil*, and ill consequence. For this purpose I especially give offerings to Apollon and Artemis, as I envision their double bows loosening arrows to destroy all that which would harm the oikos. I pray to Hekate and Artemis then for nurturing those within the household that the household grow in good health (and in the case if I were living in an ancestral home which had been handed down through the generations I probably pray too for the expansion of the household for their blessings upon new children born into the oikos). Meanwhile Hermes I give offerings to primarily to bring prosperity and good fortune as is his want.
As I live in a modern household, this means that all of these gods sit within the front doorway, and all indoors. Upon leaving I occasional speak as I am passing a small prayer, and then on returning I give offerings at their places at the doorway. This usually manifests in the form of incense, as I find that easier to give directly upon entering the house, especially in a subarctic environment where the option of gathering wildflowers or blossoms from the garden to give them upon entering is a bit difficult outside of the brief summer season. I have also had it suggested to give barley groats (though this might be more useful to be ground into a meal and kept in a jar on the altar that can be sprinkled in offering, akin to the idea of the roman mola salsa of spelt and salt, for ease and convenience. Of course offering libations of clear water directly upon entering is also useful and is often something readily on hand (or close enough to being so). This means that unlike people in the ancient world who may have passed less frequently through the doors, going out for the day for whatever business they had before finally returning, I acknowledge that I pass through my doors ALOT. This also means that I am giving offerings and prayers ALOT. But I still find it an important part of my religious practice in preservation of the wellness of my oikos.