In Sertorius there is a Race called the Hasri. Hasri do not reproduce through sex and have no gender. When a Hasri wants to have offspring this is achieved by making an offering to Sarilla. As you can probably tell from the previous sentence, this presents some issues when describing the Hasri because pronouns are difficult. We've developed some informal conventions in our own group.
One easy way around the problem would be to use 'it', but that feels a bit off since it is used mainly for objects. Another solution is to use 'they' but while that can work when talking about Hasri in general it sounds very unusual if you are talking about a particular Hasri (i.e. "Vaela was born in Caelum and at age 18 they went to Cael to work in a Scriptorium"). One player pointed out that since all Hasri can lay eggs if they make an offering to Sarilla, they would technically be female and using 'She' is probably the most appropriate choice. This works, except Hasri themselves tend not to think in those terms. Still I think that is a fair point and using 'She' seems fine here.
Outside their homeland, among Humans, Dwarfs and Elves, Hasri will sometimes adopt a male or female identity to facilitate social relations with other races (if born into a non-Hasri culture they may identify with a particular gender as well). We have had a few characters do this and in these instances, the individual Hasri is referred to using the pronoun most appropriate. I have to admit that as a GM I tend to think of certain Hasri NPCs as male or female. The character Vaela in my Swords of the Four Taverns Campaign is usually referred to with the male pronoun in my campaign logs even though Vaela doesn't identify as male at all (nor as female).
One thing we tried to do in the text, and I think this wasn't very successful, is use no pronouns at all. In places of the Sertorius rulebook, we simply repeated the character's name again and again where a pronoun would have been used. In my opinion this didn't work very well but it was the best solution we could come up with at the time.