We have a long passage in our apartment, with 7 doors, five of them identical. So guests inevitably choose the wrong door (and sometimes doors) when they need the bathroom.
We have been looking for a sign for the door that is not just WC, Toilet, or the standard man/woman picture. I was looking for something gender neutral but none of them appealed to me. In the end we settled for this one which I rather liked. They come in many different colours but we chose standard black.
I got it from the shop Wallineed on Etsy. Price was good and – for corona times – delivery was quick. The seller was also quick to answer questions. They also had these ones: