You practice, for one. I've seen worse from those who should know better. Get used to how 'you' feel. Learn to know yourself so that you don't have to consciously think about who you are. Then start thinking about putting up that wall and keeping it up. Eventually you want it to be unconscious.

[Loki smirked a bit.]

And then we get into layers and how to make it stronger. I've been teaching Eilonwy as well, so she might have advice for you that I do not.