I am not sure you will ever get past that issue. Societal normatives of boy and girl and the dress code of each is something the we have hard wired at an early age. AJ from the BeaverBunch on YouTube had some rants over this topic. Genderqueer folks have just added fire and increased awareness that we are different and will not be bottle necked into your view of who I am. In time this qroup will breakdown some of those rigid boy girl presentation problems. I would correct them and not offer an explanation or apology for your presentation. We live in a time when change of societal expectations of dress, gender and sexuality are being challenged and the younger generation will get the benfits for your hard work and unfortunate need to educate/correct others. Its okay for girls to wear boy stuff but the opposite is frowned on so if its any comfort you are ahead of the curve a bit. Good luck and I see a girl in your profile picture :>)

Your gender presentation doesn’t determine your gender identity! I get sir’d sometimes depending on what I’m wearing, but I have a pretty high pitched voice so people usually scramble to ‘correct’ themselves or whatever after I speak. Personally, I find the entire situation hilarious and the discomfort of cishet people with my gender/presentation/identity greatly amuses me.

However, if you’re wanting/needing to correct someone, I’d just do so firmly but politely. “Refer to me as she” or “Please call me ma’am/miss” or whatever feels comfortable to you. And don’t care about making other people comfortable with it. If other people are going to get super awkward about it, honestly that’s their problem.