Place Black Tourmaline in each of the main corners of your home.
If you feel a room needs extra protection you can also grid individual rooms.
With grids you should energetically link the crystals together with a wand while stating your affirmation. However, that is no so easy when you are gridding your home. I suggest you place your crystals and state an affirmation while placing them. A suggested affirmation, "My home and everyone who resides with these four walls are protected at all times”
Once you have placed the crystals sit approximately in the middle of your home / Grid. Then close your eyes, relax and focus your energy on visualising the crystals being connected energetically. As additional protection you can also visualize a white light around your home that is emanating from the crystals.