For trans women, any salon or stylist (not barber) in the LGBT area of any major city should be just fine for helping you find a style. Just pick one where the rest of the clientele sort of matches your preferred style (trendy, conservative, scene, etc). Once you find a cut/style you like, any salon anywhere should be able to maintain it.
Trans men have a harder time; if we go to a place with a big lesbian clientele, we're liable to come out looking like lesbians (butch cuts are subtly different from men's cuts). On the other hand, we're sort of in a catch-22. If we go to any random barbershop/stylist while not passing, we're likely to get a women's cut; if we have a women's cut, we're likely not going to pass when we go get our hair cut the next time. An LGBT-friendly stylist is our best bet for breaking out of that cycle, even if we do end up with a slightly lesbionic style. A butch cut can be morphed into a men's cut over time.