I hope I'm putting this in the right place.
I grew up in a very turbulent household with a lot of aggression flying around; you can certainly lock your bedroom door, but there's so little you can do to keep away from the bad energy filling the air. When you're emotionally drained, or not used to shielding it can be hard to keep yourself safe from these. The following is what I did and it helped so much more than I thought.
I took a strand of mardi-gras beads (the cheap plastic ones, as it was all I had at the time) and I said this over them, channeling warm energy through my fingers as I held them in my hands:
"To those who enter through this frame,
Though moon or mood may wax or wane,
Not one small hair shall make it through,
If carried with, are troubles new."
I said it over and over until I felt a calm secure strength between my palms. I then wrapped the beads around the neck of the doorknob of my bedroom door.
It didn't fix everything, but it helped so much, so I thought I would share it, just in case it could, possibly, help someone else.
((Yes, this is mine; I wrote this years ago.))
Feel free to let me know your thoughts. Like my profile says, I'm really new to sharing so I beg you - be kind :).