Not everyone has a sacred spot to call their own, preferring to build that ritual space each time for meditation and spellworking.
Those who do have house altars setup something special in an area of their house to remind them of the many elements of spirituality.
What to add?
Representations of the god and goddess. You can find statues online, in stores, or make your own out of salt clay, or simply post up a poster/print on the wall as well. Some representations can also be a seashell, deer antlers, or a cauldron with an athame.
Symbols of the elements. Air (east) could be incense, windchimes, fairies, bubbles, feathers, or animal figurines such as birds. Earth takes form in stones, crystals, seeds, plants, and wood. You might also want animals such as a woodchuck, chipmunk, or other earth dwelling species. Water could be seashells, a bowl of water, a fountain, or figurines of fish, mermaids, or other sea creatures. Fire (south) takes the form of candles, dragons, or salamanders.
Types of altars:
Personal altars can be mobile, stored in a box, or setup on a dresser or small table in a bedroom or closet. They are generally small, intimate, and personalized to the person.
Family altars are more prominent and generally sit within a working area of the house such as dining or living room. A family altar also has a number of items each member of the family feels necessary. These can change seasonally or through special times in the family’s life.
Outdoor altars can be found in gardens, play areas, patios, or porches. These are often setup seasonally and used with devotional rituals or moments of meditation.
The important thing with any altar is it reflects your spirit and spiritual needs at the time.