Building altars is a deeply personal process. Some people build an altar of stone and mortar, other build it out of paint and sticks. Many people build an altar out of flowers and shiny stones.
The question isn’t what you use to build the altar but what you wish to alter when you build the altar. Altering your surrounding to create and manifest what you desire and what you require is a gift we give ourselves.
I build my alters as visual mnemonics. My interior castle is reflected in my exterior castle. As I purge things from my life I find my mind clears and my body heals. I try to build my entire house as a living breathing altar meant to alter my perception and bring forth beauty.
So now I build my mini altars within the altar of my home.