An altar is a focus for devotion, prayer or meditation. It can be simple or complex, small or large. It can have no images, a single image, or multiple images. It can be themed around a particular idea, deity, holy person or festival. You can have more than one altar or shrine around your home.
If your altar is for meditation or prayer, choose a spot in your home that is quiet and peaceful. Consider how you will use your altar. If you are going to place flowers on it, or use it in ritual, make sure there is space for everything you need, and that the altar is easy to keep clean. Some people like to light a candle or ring a bell before they start their ritual, meditation or prayer.
The typical altar might have a bell or singing bowl, some holy pictures or statues, some natural objects such as pebbles, shells, feathers or wood to make a connection with Nature, a candle, prayer beads, and perhaps a holy book. It may be a shrine to a particular deity, saint, Buddha or bodhisattva, or to multiple sacred foci.
In Orthodox Christianity, the shrine at which the family prays is known as the Beautiful Corner, and is decorated with icons of favourite saints. Icons are seen as windows into Heaven, and depict the transfigured face of the saint. Before praying, people will light a candle and cross themselves.
In some traditions, people build altars or shrines at particular times of year. In Mexico, people build shrines for El Dia de los Muertos (the Day of the Dead) to commemorate their loved ones who have died. There might be photos of the loved one, together with their favourite foods, and flowers. Many Pagans around the world have borrowed this idea. Clarissa Pinkola Estes, in her classic book Women who run with the wolves, describes how women built altars to commemorate losses in their lives, and how this helped them to grieve properly and to recover from the trauma. You could also build altars for particular rites of passage, such as the transition from childhood to adulthood, or for marriage or divorce. The altar might include symbols of the phase that is coming to an end, and symbols of the new phase to be embarked on. You could even build one altar for each phase, and then have a ritual progression from one phase to the next.
Another way of making an altar is to find a special tree or rock, and decorate around it with found (but biodegradable) objects arranged in a pattern, such as twigs, leaves, berries and feathers.
There is no right or wrong way to make an altar. Each altar is personal and special. If you are following a particular spiritual tradition, it may have particular ways of making altars, but even within that, there is plenty of scope for creativity.