I've been meaning for years to reply to this thread
My altar faces east, it is very beautiful when the sun rises. In the middle I have a soapstone oil burner that I burn essential oils, resins, and water. I keep the water for my oil burner in a green happy buddha beer bottle, it just makes me happy every time I see it
Sometimes I put a flower or two in the belly of the buddha.
On the far left I have a jizu statue (a protector of women and travelers) I love it's peaceful expression and prayerful stance. Then I have an abalone shell with a small bundle of white sage from the hiking trails near where I used to live in California.
Next I have a Chartres Labyrinth candle holder with small sodalite and citrine pebbles surrounding a blue candle. I love the message behind the Chartres and other labyrinths. Unlike the maze with dead ends and tricky passages to choose from. Labyrinths have one winding path leading inwards with the same path leading you back outside.
I also have a small rock I picked up on a beach on a beautiful windy rainy day celebrating with my friends as one of them was about to be married. Then there is a brass colored lotus blossom candle holder with a reddish brown votive on it.. And finally my favorite piece a warm golden clay mother goddess mini taper candle holder. I put in a different colored candle in it depending on what I want to meditate and focus on when I light my altar up. I usually take my altar down the next day after lighting my candles because in the winter time it is too cold not to bring down the shutters which in turn knocks half of my altar off the ledge.
All of this is on the ledge of my bedroom window facing east. I think part of having an altar is the moving meditation of putting the altar up, then packing it away. In roman catholic mass, as an altar server I used to have that as one of my duties. During special masses we even incorporated the putting up and packing up of the altar during the quiet interludes between spoken and unspoken prayer and reflection. First preparing the altar and preparing ourselves for prayer then putting the altar away to prepare ourselves for going out into the world and doing good in both words and deeds. It's what I miss the most about organized religion. The milennia of tradition and ritual perfected and practiced by millions.