@Jedigirl Why do I worry about it? I do not want to disrespect someone by misgendering them. I work in a hospitality field where the use of honorifics is expected. Messing up on 'Miss' or 'Mister' is bad guest service. And Mx. sounds too much like Miss with my dentures.

I am open to suggestions...

@oldoldcojote
Sadly, asking did not work very well for me. Some cis-folk were offended because 'it should be obvious'. Some trans-folk would interpret my polite inquiry as an attack on their gender expression/identity. And asking about pronouns is too controversial in my (overtly anti-LGBT) state.
All we can do is try our best to be polite.