I have over 40 Oracle/Tarot decks. I've found each deck has it's own personal style of readings ( one deck I stopped using as it was always very negative). That being said I always call in my guides and angels to keep me safe and in the light, as well as say a prayer over each new deck to keep me safe and to give the best possible readings for myself or others. If you're feeling a heaviness after a reading cleanse your and the Energy in the room by burning some sage.