I believe that cross-dressing is part of spiritual development. I know that may sound crazy but that's the view I have come to after many years of thinking about it (I am 52).
A few things have led me to this, firstly that the need we have to express the feminine part of is very strong and deep within us. We are unable to eradicate these thoughts and feelings no matter how hard we may try. They seem to touch on something very profound. However as it is also mixed with feelings of guilt and perhaps eroticism we sometimes don't realise that this could be more meaningful.
Secondly, I've read quite a bit of Carl Jung and also other esoteric literature (including Qabalah). Carl Jung refers to the 'anima', the normally unconscious feminine side that all men have (women have a corresponding masculine aspect the 'animus'). Part of Jung's development (a process called 'individuation') is to recognise the anima, bring it to consciousness and then reintegrate it into the personality. This is also an idea reflected in the Qabalah and in alchemy.
I believe that cross-dressing is a reflection of the desire to develop ourselves by bringing forth the anima - expressing it (her) physically (the physical aspect makes her more real and brings in the emotions) - and then reintegrating her. If we then accept this part of us - as a true and worthy aspect of ourselves - we can move towards a more complete and intergrated personality.
I'll stop there for now - but am very interested to hear what others may have to say on this topic.
By the way, thanks to LynnR for prompting me to start this thread. I touched on this in my intro and Lynn said she was interested in what I said then but couldn't contribute because the thread was closed.