One of the things that attracted me to Catholicism was a home altar I once saw in a person's house. It was a simple affair really, with a small statue of Jesus and Mary and a candle and Bible. Nothing to it. But resonated strongly with me and when I became a Catholic, I built myself a home altar. I love it.
When I became a Christian Witch, I found that the home altar was a integral part of witchcraft and casting. The home altar becomes your sacred space and this is where you gather energy to cast and create and work magik. Altars are very personal and can be as simple or as elaborate as you wish.
Now, there are a lot of witchcraft writers that wool you about directions you should have your table facing and the shape of the table and what you should have on it. And that is fine, if you want to follow a formula for a while until you get a sense of how you use sacred space. I follow only few rules for the creation of an altar.
Think about how much space you have and how you plan to use it. Are you going to have large pieces of art, a large Bible, and a big cauldron on your table? If this is your plan, buy a nice big table. I wished I had more room because I would actually have a eight foot table set up with the main part of the altar in the center and then work surfaces with my book of shadows and cauldron on one end and my Bible and Prayer book and candle array on the other. I would also have storage underneath for all of my witchcraft books and supplies. But as it is I force myself to work in a rather small space so I don't go crazy.
Next think about efficiency. Are you a frequent duster? Or do you dust about once a month or just before a ritual? Are you a neat nick or a clutter bug?
Next think about devotion. If you are a Christian, are you devoted to Jesus Passion? if you are, a nice Crucifix might be great as a central image. You might use pictures or plaques instead of statues to cut down on use of table space. Do you have a sacred fire? If you are like a lot of us, you might not have an actual hearth so a nice large pillar candle may be serving as Sacred Fire. You may also want to have your Bible on display. If you do not already have one, you may want to get a slimline style that is small, or use a New Testament with Psalms and Proverbs.
If you use a cauldron, it is fine to have a really big one, but if you are using a small table top, you may want look for a small one. And one of the things I use to actually cook potions is a simmer jar that is suspended over a tea light. We rarely cook large amounts of potion any more and you can cook it thoroughly and when it cools decant it safely. It also saves plenty of room for your work.
It is great if you have room for your book of shadows on your altar, but what I do is usually take the pages out of my book (my BOS is a three ring binder) and cast using the pages. It makes for easier reading and handling. You can also jot down the spell and take it to your altar.
Above all, have fun with your altar. Think of it as you magikal platform or room. Try to use your imagination and by all means honor who you are and express your best relationship with God
Brightest Blessings Be