In response to my post asking for questions, Kas wanted to know more about making shrines:
How an altar should look varies, of course, depending on the spirits being honored and the local culture and religious context in which that is happening. Home or business altars often reflect the larger temples where they exist. Some people, generally those who work with a large number of spirits for whatever reason, will have entire rooms devoted to shrine space. (The house Mari and Robin take over from their aunt has such a room.) Most people get by with considerably less than that. There's no "official" way to set up a shrine or altar for any of these spirits, though there is iconography and styles of figure that I associate with my work.
One of the most common locations for a shrine is at the hearth. Sometimes this is given solely to a hearth spirit like Mara or Brhenti, or to the spirits of the home and land, or both. Sometimes there is a single main altar for a home situation at the hearth, and so other spirits and ancestors are also honored at the hearth.
I have personally found myself moving more and more toward altars that look like gallery or collage walls instead of table or shelf-top artscapes. My main altar currently features framed art and little tchotchke shelves that hold deity representations, offerings, and related items. There are also small decorative shelves that were built into the house we're renting which I use for shrine space, including the ancestor altar, and I repurpose pieces that were originally designed for hanging specific items, like key holders and plate displays.
I still have a pretty wide variety of deity representation kicking around, but I find myself leaning toward a specific aesthetic where humanoid spirit figures have blank faces, to represent how any icon or statue is not going to be able to capture the spirit, and sometimes iconic wings to represent their energy. I'm still experimenting with this aesthetic, though, and plan to make some forays into creating my own deity figures in the future.