You will be hard pressed to find a religion or a spiritual path that in one form or another does not make use of an altar of some type. An Altar is a sacred space either for use in Rituals or Rites or for personal meditation or reflection. It can be made to honor ones Patron Gods/Matron Goddesses, your ancestors, or simply as a place to store your tools and do your Ritual work around. It can be on a special table, a book shelf, the top of a chest or dresser, or stored in a box. It can be kept up year round staying the same, kept up year round with it changing as the Wheel of the Year changes, or it can be taken down when not in use.
Aesthetics – How it looks, and the visual feeling it gives. Does it have its own aura? Does it create a ‘sacred’ space? Is there room for comfortable meditation in front of it?
Balance – Are the objects balanced to each other visually? Is it “spartan” or overly crowded? In my opinion, objects of quality, if fewer in number, are better than a clutter of cheap items. Are objects easy to grasp smoothly without clumsy fumbling or shifting things during a ritual when needed?
Lighting – All temple areas should only be bathed in candle light during ritual use.
Scent – This is overlooked sometimes, but aroma/scent creates mood and atmosphere and opens the mind and is important. Don’t use cheap incense. Get the better brands or use high quality resins or oils in oil censors.
Safety – Are the candles placed so they don’t set your robe or your house alight or drip wax over the altar cloth? Are your oil censors placed where they wont be tipped over? Athame where it doesn’t fall off on your foot? Cauldron where it wont burn or scorch your altar table or altar cloth, does it need a heatproof tile under it?
Like many things in Paganism, the set-up and what is on your altar is entirely up to you. My wife and I have the bedroom altar which has things on it that mean something to the two of us as a couple (the glasses from our wedding, the rope used to handfast us, flowers from her wedding bouquet, etc).
The Elements / Quarters
With Air (East), Fire (South), Water (West), Earth (North), all the elements represented. Earth is usually a bowl of earth, Air an incense stick or cone, fire a plate of coal, and water a chalice full of water.
Goddess and God
Some people recommend a layout with the elements and the Goddess and God represented. The candles for the Goddess are usually on the Left while the candles for the God are on the right. The goddess is usually represented with a silver candle and the God with a gold candle.
A pentacle is usually in the center of all this. With an Athame on the right and the wand on the left and a spot for the book of shadows.