Hi Holly,
I use crystals frequently. It is really important to NOT over-do at the beginning.
Crystals, all of them, have their own energy.
Each crystal will multiply the energy of the crystal(s) nearest it.
And the next one will mutiply the next.
And so on.
In other words, they tend to muliply exponintially (sp) continually.
SO, If you make a grid of crystals, place yourself and a crystal in the middle, you magnify XXXXXXXXX's infinitly.
In case you are wondering, NO this is NOT scientific in any way! I just know that it is.
Start small, and work your way up. The size of the crystal is not always a good indication of how much energy it carries.
Having the crystal clear and programed, is essential.
I also did the grid thing to myself (some time ago) per one of Diane Steins books, and had some really wierd dreams for several days after. It was interesting, but I don't make a practice of it. ;o)
By the way, you put them where it feels 'right' to you. You might just try the tiger eye on your third eye, I am told that if you wear a tiger eye, people have trouble lying to you...
Love and light, Priestess