I was given the following advice a few months ago when I was struggling to fend off negative energy:

Close your eyes and envision yourself being protected from a light beam that begins at the very top of your head, then slowly wraps you in a warm shell and it goes all the way to your toes, tucking under your feet. Nothing can permeate this light wrap. Stay in it until you feel peace. This advice would've sounded crazy a few years ago but now it is a very useful tool for the intuitive human!!!