I am a certified Crystal Healer in two lineages and Master Stone Grid Practitioner, as well as an Usui and Karuna Reiki Master Teacher, and Crystal Reiki Master. Recently, I've been playing around a lot with crystal grids for the weekly Reiki Distant Healing event on my Reiki Facebook group, REIKI FOR YOU AND ME, setting up a different grid each week for that purpose.  I also have several grids set up for different people who have some pretty serious issues and need a little something extra and one in my healing space under the massage table. Crystal grids are a great alternative to sending Distant Reiki Healing the standard way using symbols. 
After doing several of them, I discovered two extremely interesting and powerful things about combining Reiki with crystal grids.  One is you can charge it after you activate it with Reiki and send Reiki to it every day or every other day to re-charge it. You can check in with your guidance using muscle testing or dowsing with a pendulum to see when it needs recharging.  Here is one of my grids, stare at it or call in the energy of it in meditation and feel the energy!
The other is even after you have taken the grid down and it no longer exists in the physical world, just looking at the grid in picture form will give you the same energy it gave out when it was created, activated and charged.  This was brand new and mind blowing information for me!  Stare at this grid for a few minutes and see what you feel.  You might even call in the energy of the grid if you know how to do that, in meditation.

If you are interested in working with crystal grids,  I suggest you invest in a book on crystals/stones like "The Crystal Bible" by Judy Hall or "The Book of Stones" by Robert Simmons and Naisha Ahsian. You will need to know the properties of all the crystal/stone so you can make educated decisions about which ones you'd like to make your grid with.  There are so many books out there to choose from, these two are just some of the best ones I know of.  Again, use these books to choose which crystals/stones you would like to have in your grid, based on the purpose of the grid (your healing and what issues), or whatever other purpose/s you would like for example: World Peace, for a friend or relative having serious health issues, or to break an addiction.  Books like "Crystal Grids" by Hibiscus Moon will teach you how to set them up (arrange them geometrically) and how to activate and charge them properly.  There are a slew of books  on Crystal Grids out there also.

If you don't have a local crystal/stone/rock shop in your area, you can always order your supplies on line.