Playtest with people from diverse backgrounds for sensitivity. Details that you might not see could cause unintended harm.
In the early version of the well-acclaimed game Ticket to Ride, you could see a star on the yellow trains that resembled the yellow star of David. Many players saw a possible association with the practice of Nazis during World War II to label Jewish citizens who were transported in train cars to concentration camps for the most. Fortunately, the mistake was corrected in the reprints of the game.
Playtest with people having different abilities for accessibility. What might seem obvious or easy to you can be more difficult to others.