For feeling gigantic, it’s very similar to domme space. I just enter a headspace of “im huge, im gigantic, im interacting with someone who i feel is beneath me,” depending on the character. For feeling small, it’s kind of the opposite. Although to be honest i think tiny and prey are natural states for me, whereas giantess / pred is more of an indulgent role to step into that I’ve only just embraced over the past year