Asking folks for their preferred pronouns (she, he, they, zie) can be a delicate matter, so I've devised a highly British approach: ask them how they like their tea. Simple, effective, with a clean design.
A detail view Dietary Requirements. Like many things, dietary requirements can be fluid: sometimes folks might like to avoid gluten and dairy products, but it's not essential (and some times it is). Here, I'm using colour to indicate strength and importance of the preference, and as a feedback to the user that their preferences have been recorded.