Adrienne, Protection is a must; I also use crystals as I find, each has different, built-in features, which, depending on what I am meditating on can both protect and assist in meditations.
I also carry a special one when I am going to investigate the presence of a spirit. This helps Protect me and also make a better connection with the spirit.
With the exception of one sighting of the spirit a few months back I usually "feel" their presence and can bond with them to get fast "pictures" of their life in the physical world. This helps me to talk with them and finally assist them, with the help of some spirits in the spirit world (I am lucky to have such help, which only began 18 months ago), cross over.