The Alter is a magick place. They can be any size, shape and can be made out of almost anything. For example, they could be a windowsill, on top of a little table, on a chest of draws, or anything you can think of. Few people have temporary altars just setup for rituals. Altars are very personal to you because they hold your thoughts, and can look like whatever you choose. Lots of altars have different things on them and characteristics. For example:
Goddess and God figures:
Small statues, figures, pictures, or candles to represent the Goddess and God. If you're using candles then the Goddess candle is traditionally silver, white or green. The God candle can be red, yellow or gold. The Goddess candle should stand on the left of the altar, at the back, and the God to the right. The tools of the Craft are associated with either the Goddess or the God, and should be put on the according side.. TOOLS:
There are tools associated with the Goddess are the cauldron, penticle, bell, crystals and these should be put on the left of the altar. The tools associated with the God are Censor, wand, athame and bolline, and these should be to the left of the altar.
Your altars can also be outside, you can make them just near were you live. Also when you have a altar outside make ure you are somewhere where you can't get disturbed. Also Having an altar outside means you can be by nature and shoud get some peace. But in winter it would be very chiily.