In addition to what's been suggested, I highly suggest learning Shielding techniques, which are very common and essentially consist of concentrating energy around your body to dull your sensitivity to outside forces, or protect yourself from outside harm. You can find various techniques all around written media and even video sources, and many techniques include manipulating the "Aura" around your body, which you can also find further information on--far too complex to explain in a paragraph or two here.
Just keep doing research. The more "contact" you have with spirits, the more your reflexes will sharpen, just like using a new muscle.
