Altar question

What all can I add to his altar, i can't have any plants or candles because it's in the living room, and i can't get a statue because i live in a different region house, my friend said she might be able to ask about getting me a devotional necklace on etsy (my parents don't trust etsy) so what all can i add to his altar that wouldn't bring up any suspicious i might be worshiping a different god or being in a different region?