No matter how elaborate your altar, everything on it should be clean and meaningful. Nothing can be placed there that doesn’t have a purpose. I don’t care if the rest of your home is a filthy hoarder disaster waiting for an HGTV crew to clean it up—your altar must be clean and nothing on it should be left to rot. If there is liquid in anything (oil lamps, water bowls, and so on) they must be changed regularly. If there is incense, the ash must be taken care of regularly. Treat it like a living thing, because on an esoteric level, that is exactly what it is.
Very necessary for a perspective that a lot of operators dont take into account. If you don’t want something negative to manifest you should definitely take notice of what is out on your altar.