Needless to say, not everyone has three altars (or even one--if you don't have one, this might be a nice time to create one as a spiritual center to your home). But if you have even one, it is a good idea to periodically clear and cleanse it--nobody likes a dusty altar--and check in to see if it is still what you need in its current incarnation.
My main altar, in the dining room/office, gets cleaned pretty often for the most part, since I use it the most. I did, however, find that the top section was dusty and that some of the items that had been living up there no longer seemed right for the space.
It feels really good to clear away the dust and cobwebs of the old year, and start out fresh.
Do you have an altar? If so, what kind of things to you have on it? And have you cleaned it lately?