while you should cast spells for yourself because they'll work better, protection spells especially should be done yourself if you're protecting yourself. a simple one you can do daily is while meditating, visualize a white or silver ball glowing brighter and brighter, then, it grows and forms a circle or cone around you. you could also wear some charm or crystal, once a month, you should rebless it. normally visualize white energy entering it, then say a chant. you could also leave it in the window during the full moon to catch its light.