When is a Shield Needed?
When you use a protective shield is entirely up to you. Only you can determine how much energy or psychic entanglement you can tolerate or want.
A good place to start would be determining what situations or people tax your energy the most. What environments are you more at risk or susceptible in?
Consider: Imagine energy is a little like the flu, or COVID. Every time someone coughs, breaths or sneezes they send out some of their virus that can infect the people around them. So, when do you need to think about protecting yourself from the flu?
Times you might think of using extra precautions to keep yourself healthy might include...
When you're around sick people
In an indoor space or crowded area during flu season
When you visit a hospital, pharmacy or doctor's office
Precautions you might take could include wearing a mask, washing your hands more, using hand sanitizer, at the store, not shaking hands or kissing, maintaining a bigger distance between people, taking extra vitamins, or staying away from places you are likely to encounter the flu altogether.
A shield can similarly be useful when you are likely going to be in proximity to people who may overwhelm you on an energetic or magickal level, psychically drain you, etc.
Often certain people or situations seem to drain us more than others. There are also times when we feel especially vulnerable or at risk emotionally and mentally, such as being at a family gathering with an unkind or vexing relative, attending a public gathering where you'll encounter lots of strangers, or having to work with someone who gives off a 'predatory' energy.