From the article "Reality Creation Redux" on the montalk.net website, http://montalk.net/notes/reality-creation-redux

1) Awareness / anticipation repels.

2) Ignorance / denial allows.

3) Intent / emotional resonance attracts.
I found this article inspiring and clarifying. And it seems like employing these three simple tenets could go a long way in psychic self-defense.

Lucid dreams, and the astral, are fantastic testing grounds for these ideas. I've experimented directly with them and have found that, in dreams anyway, I can stop certain effects by placing awareness on them. If I take my awareness away, the effect may manifest again, through the interplay of 2 and 3 above. Too much of 3 (emotional resonance) can override 1.

The main trouble it seems, in all cases with Negs, is that a person's emotional resonance is being negatively influenced. And it rarely, if ever, seems to be enough for a person to merely to become aware of a psychic attack in order to throw it off.

Successful psychic self-defense appears to follow the above principles. Through increasing your awareness, discovering and minding your blind spots, and maintaining positive attitudes, a person is able to execute the countermeasures needed for a long enough period of time so as to throw the attack off. These three things by themselves won't necessarily end an attack, but it's hard to see how an attack could be stopped without them.