Self crossdressing is about freedom of choice, excitement and the probability of passing (= go to public undiscovered). I image an attractive, sometimes conservative dress, and image to go for shopping or travelling, being a tourist somewhere else in the world. This is the illusion that I could be someone else, someone who is just a visitor without id. I can take pictures and movies about myself, and nobody knows that I'm not a girl.
Forced crossdressing is about defencelessness. I'm a submissive male with 1-2 dominant women. We are having sex each other, but on one condition: every time I have to be more and more feminin (starting from the invisible parts e.g. g-string and stocking, through the hideable parts e.g. bra to the obvious skirts and high heels). I have to go often into the public, shop clothes for myself in the women's department. The domination can be extensive (definitely not wanted in real life): I have to take extreme photo-shots, I have to show myself as women to my collegues, and I have to date, flirt and indulge men. Sometimes it is connected with forced womenhood and magical transformations.
I can't be transsexual, because I couldn't stand hormones and surgery, that means I'm crossdresser (or transvestite). Unfortunately these desires all not always sexual related. There are times when I'm watching women clothes, and I would say: "I'd be pretty in that".