I think it could be useful for your own interest (and trans clients) to take a workshop in queer competency training and/or research lived experiences from trans individuals. Gender dysphoria can certainly influence mental health, although some trans individuals do not experience dysphoria. If you respect pronouns, don't ask unnecessary invasive questions, and use gender-neutral anatomy (e.g glans, chest) that will help. I am speaking from personal experience from having numerous trans friends and working within the queer health community. I'm still a psych nursing student so excuse my lack of jargon. You could check out in Whipping Girl: A Transsexual Woman on Sexism and the Scapegoating of Femininity by Julia Serano, websites like everyday feminism, or even blogs. If your city has an LGBTQ resource centre you could contact them about getting some training.