Not sure if you're asking me but as far as I've heard from many transgender or intersex folks, it's not malleable like that. Many simply feel that they have been born in a non-matching body. So there's as much "Oh today I feel like a dude" and "now I feel like a chick" as there is for a cis-gender person (that is, people whose body and gender identity match). As for gender fluid/non-conforming folks, I think it's easier to think about those gender identities not as constantly flowing between male and female but as breaking that binary and feeling at ease in a space in between. There exists some confusion over this because of the term "gender fluid" but my understanding is that the word fluid in that term is used specifically to refer to a fluctuation within the bounds of male and female. So one can possess more conventionally "masculine" characteristics and still retain some "feminine" characteristics or reverse those ratios or anything in between. The thought of using different genders to their advantage is usually a highly repugnant idea to most trans folk due to the likely excruciating mental confusion and angst that they had to suffer to inhabit their own gender in the first place, making instances statistically insignificant. (This statement being more aimed at cis-gender people who worry about trans folk using their bathrooms/change rooms, etc.) A wider umbrella term is "genderqueer," which helps to coral most of these terms together. And, of course, as with most things in life, but especially with gender and sexuality, there is no true consensus within the genderqueer community.