Engaging in little activities like shows or coloring or using my little plates/sippies, or wearing certain clothes can deepen my feelings of being little, but about the only time I don't feel at least a little little is when I'm having to deal with big crisis level stuff.
Only a few people I know IRL know about my little side, but since they know me well, it wasn't so much a revelation as just an explanation or name for why I like some of the things I do. Mostly I just act like me, just as I always have, I'm just a little more confident about it, now. And those who don't know (which are most) probably think I'm a little odd, but I don't mind.
For me, it's easier to reign it in around people who wouldn't get it than force them to recognize my littleness. I can be authentic to myself and still be situationally aware and act appropriate to the situation (work, social, etc.)--the two aren't mutually exclusive and I don't need them to validate my identity as a little. But I also don't want to make them uncomfortable or open a can of worms having to explain it to the vanilla community I live and work in, so like I said, I reign it in