I usually go to the women's bathroom because when I go it's always some place where someone knows me (and doesn't know I'm trans) or I'm with some family member, and I'm not out to everyone. For example gym. I don't really use the bathroom and locker room there. But if I really need to go, I go to the women's one because the gym owner and the trainer know me and it's not like I want to come out to them. And I don't need to. I'm pre-everything and I don't think people there need to know or would be able to understand. As I said I don't really use the bathroom there (I pee before going, and I don't pee every hour, so....) and I take a shower when I go home. So I don't see it as an issue there. I simply avoid both locker rooms/bathrooms. Problem solved.
But if I'm alone somewhere and no one knows me I'll use the men's bathroom. Because I fear I get weird looks in women's bathrooms. Maybe I'm paranoid but I think it happened a few times. I look like a young cis guy, I don't really want to scare anyone in the women's bathroom. It's difficult, because I really pass most of the time but if there's someone I know around me who doesn't know I'm a trans guy (family members, college friends, just to make a few examples) I just can't go to the men's bathroom.
If I see unisex bathrooms I use those, obviously. My college has many of those, but some are gendered. I find gendered bathrooms ridiculous. All bathrooms here have closed stalls, doors can be locked and there's no space below doors so no one could spy. Then there's the sinks area. Still, most bathrooms here in my country are gendered. i just find it stupid since stalls are closed and doors can be locked.
Once I start HRT I'm pretty sure I'll never go to women's bathrooms again. My voice is already masculine and might sound androgynous like people can still doubt....with T though, it will get deeper and will not be androgynous anymore and there will be no doubts after some months or years on T. And facial hair will start growing eventually. So I'd never risk like that, no matter what I have "downstairs".