I love using crystals when I do readings
I also use them a lot when I do massage
For readings I generally use the same crystals split between my left (for giving as it's closest to the heart) and right (for receiving) pockets.
Herkimer diamonds - I have two which I put in both pockets to help connect to both higher powers and my client
Sodalite - I started off with one but it has now become two as it split along a fault. I put a half in each pocket to help with communication (mine, my guides, and my client)
Smokey quartz - sits in my left pocket for help with grounding and to help me limit how much of my energy goes out
Sugilite - on my right for it white light shield and help with divine love and guidance
Labradorite - on the right for enhancing my intuition and psychic abilities, and for its protecting and shielding properties.
Spiderweb jasper - I made an anklet out of these beads to help me with grounding and seeing connections
I also have a little stone (from my garden) shaped like a lizard head that helps me connect to my ancestors
Black merlinite (aka psilomelane) - currently in a sling around my neck. So many reasons for this one!
Staurolite - I was using this one (in the sling the Merlinite is now in) for a while to help me connect better to my faerie guides. I'm trying to wire wrap it to put in on a chain but that's turning out to be harder then I thought lol
Occasionally I'll feel the need to add others as well like rose quartz, moss agate, or my new piece of iron pyrite that looks a bit like a dragons head.