Shapeshifting requires the ability to transcend your attachments, in particular your ego attachments to identity and who you are. If you can get over your attachment to labeling yourself and your cherishing of your identity, you can be virtually anybody. You can slip in and out of different shells, even different animal forms or deity forms.
The material world is all feminine. The feminine engergy makes the non-manifest, manifest. So even men (are of the feminine energy). We have to relinquish our ideas of gender in the conventional sense. This has nothing to do with gender, it has to do with energy. So feminine energy is what creates and allows anything which is non-manifest, like an idea, to come into form, into being, to be born. All that we experience in the world around us, absolutely everything (is feminine energy). The only way that anything exists is through the feminine force.
There are Tantrics who deliberately seek to do more active forms of renunciation, so transgression of social norms and breaking of taboo, and breaking of social taboos especially, is a form of renunciation.