Make it simple. One room says “penis” the other one says “penis” with a circle around the word and a red diagonal line crossing it out. Like no smoking.
If you have a penis you use one bathroom. If you don’t have a penis you use the other.
Gender neutral. Problem solved. I have no problem with a tranny who has lopped it off going in with the women.
I do, for the real women's sake. This is going to lead to the point where any man can walk into a woman's lavatory at any time, and that's not good.