If there is a Servant I call on a LOT, it's definitely the Protector. My country isn't very safe and I am more than a little anxious and worry a lot, so having a little extra help to keep me safe makes me feel better.
The Protector is that bodyguard/guardian angel who watches over you and moves you away from trouble, keeps you safe and sound, and deflects harm trying to come your way. You can ask Him to protect you at every moment you feel the need to be safe; in a reading he comes up to warn you about dangers lurking around and to remind you He's there, and you can petition for Him to keep you and those you love protected, physically, emotionally and spiritually.
I usually ask Him to follow me and keep me safe when I go out of my house, or send Him towards those I want to be safe during upheavals or dangers. I have also asked Him (along with others) to help me keep those I love safe, and to set up better boundaries so people who once diminished me are left out. I usually offer Him candles, but if you want to give Him a more personal offering you can give Him a small shield or trinket resembling one, a photo of those you want to keep safe and such.