This was prompted by a discussion in a private group concerning how draining readings can be, especially in a public setting, or in a space designated for this kind of work where many people are giving and receiving energy and information.
If you have provided divination services, given readings of any kind, you’ve run into certain types of people. They want to take home the cards that came up for them. They tell you you are wrong because you’re not giving them the answer they want to hear. They keep pushing for more information than what they have paid for. These are physical ways in which clients cross boundaries but for some reason, others have more insidious tactics.
When it comes to crossing boundaries between client and reader, I think a lot of it comes from entitlement. Weather subconscious or not, this can present as intentional energy theft, where a client is tapping into your power to drain it for themselves, or may even be attempting to do this with spirits who might be assisting your work. There are positive and consensual ways in which energetic vampirism is practiced, and if anyone would like a piece on this let me know. But as a reader you must receive a small amount of the clients energy, and for a good metaphor you can use the visualization of a thin string connecting the two, in order to receive psychic insights, information from spirit guides, or be able to interpret what cards, leaves, or throwing systems of divination are revealing. Unconscious energy vampires have a tendency to stir up negativity and drama, and latch onto pretty much anyone who is a good source of power. Someone who is aware of their abilities and using them in negative ways intentionally might have loaded that energy connection between the two of you with a something that creates an energy conduit. This is usually a spell that might be triggered by a phrase they speak, or by shaking your hand. If they are unconscious, they may just keep coming back to you to ask for readings on the constant chaos in their lives.
Some might take it further than that. If they are attention seeking and an active magic practitioner, this may be an opportunity for domination magic. This can go hand in hand with energy theft. They want your focus on them. They want you to work for them, delivering information that suits their means and motivations. This is again done with physical contact, them handing you an object such as money, handling divination materials that you will then work with, or even something they say as a trigger. You may inadvertently give a magic practitioner access to your energy long-term by handing them a business card with your name on it. They can also work with your photos online.
It can be difficult to protect yourself from energetic aggression when in a room with a lot of exchanges taking place, such as at a public event. Running a piece of nuummite, one of the most powerful banishing stones, over yourself and your tools after each reading is a good place to start. Taking a saltwater bath after the event is over to clear any unwanted connections is another basic strategy that is very effective. You can draw protective symbols on your body under your clothing with eyeliner, and wear a piece of hematite as a pendant, which has a reflective mirror like quality. This is literally to reflect anything negative being sent to you back to the semder in real time.
If we want to get a little more in depth with protection, you could get a spirit companion. How this works is, you go to someone who conjures spirits, and you pay for a spirit who is known for protection and dealing with psychic attack. Angelic spirits are good for this especially. With enough study you can learn to do this yourself but this is actually something I suggest public readers do. Have a spirit companion you’ve adopted specifically to provide protection when you are doing readings or workings with anyone. Because you don’t even necessarily know the motivations of people you have regular contact with. If this feels a little bit too intensive, because spirit companions do require interaction on a regular basis as well as offerings, you can go to someone who will help you discover your spirit guides, and begin a regular communication practice with them. These are spirits who have chosen to stay with you, or who might have been assigned by your higher power or powers to assist you. In both situations, these spirits will give you insights if you have good communication, and may interfere when there is an actual threat.
As readers and practitioners we should be able to expect an ethical energy exchange. We open the door for people to come to us and get what they need. But we respect their autonomy in who they seek out services from. What they owe us in return is listening, taking in what information we provide, and analyzing how it makes sense in their life without ego, while also not overstepping their boundaries and invading our energy. A vast majority of the problems people create for themselves, and the issues they project onto those around them, come from unchecked ego and feeling entitled and/or insecure. So respect for boundaries is something most of us are actually awful at. The best we can do then, is defend ourselves. I’d also recommend protection work of some sort on business cards and online photos of yourself. 
Solaria Divina 