i've been in therapy for a couple of years over issues bigger than crossdressing. I've mentioned that about half of my wardrobe is from the woman's department fairly early and the issue was a side note in a few sessions. A few sessions ago, the other issues seemed to have been dealt with as much as possible without dealing with my style.
I went to the next session wearing a very androgynous outfit consisting of black leggings and a basic woman's t shirt. The session went well and we talked about further dressing for the sessions. For the next session, I had just bought a long black dress, very flowy. the spaghetti straps were at the neck so the width of my shoulders were on display. I had bought a nice costume necklace to go with it and wore some wedge sandals.
I've been working with this therapist and the trust has been established and she did make me very comfortable as we talked. Except for how amazing the dress felt I really settled in to a mode where it felt natural to sit there and discuss issues without tension.
About half way through the session, when things were at a fairly light point of conversation, she sort of stopped and told me "I have been looking at that dress and I just love it. I mean, I would really like to have that dress." It caught me completely off guard and was amazingly affirming of my taste in clothes, if nothing else.
It's still early in dealing with the cd issues but it looks promising.