My core tips for intuitive card readings:
Happy thoughts, happy feelings, smile! Just approach a reading in a natural state of joy, playfulness and unconditional love. Taking on this approach is very important because it keeps you in a high vibrational state and you will not be affected by other people's energy or what the reading comes up with. Additionally, you will channel more easily in this state.
Invoke divine help for every single reading. From Source/Supreme God, Gaia, higher self & true spirit guides (yours, and theirs). This is important they can help us better when we verbally call upon them. Like opening the door instead of talking through the window.
Ask them for healing, guidance, channeling of accurate information, holding the space. Same reason as before.
Example: I call upon the Supreme God, Gaia, my higher self and my true spirit guides and angels of benevolence and light. I also call upon X's higher self and X's true spirit guides angels of benevolence and light. I ask for the specific channeling of truth, healing and wisdom, which will serve divine will in the highest interest of all. I also ask for divine protection, please hold the space for the entirety of this reading. Thank you.
Once the reading is finished, thank all the divine help you have invoked and cut the cord straight away with the person, their higher self and their spirit guides.
How to cut the energy cord? Imagine this energy cord connected to you, and cut it in any way that works the best for you (scissors, hands). See it dissolve away from you and back to them; see your energy come back to you all pure if there's any. I also say out loud "I cut the energy cord with X, their higher self and their true spirit guides. Cut, cut, cut (while doing cutting hand motion on the cord, bc I cut with the white light that I project from my fingers), thank you".
And all of this doesn't even take much time at all if you try it. Yet it really makes a difference. I have done readings for 5 people in a row, face to face, and I wasn't drained at all physically, emotionally or energetically. Actually I tend to feel hot lol.
Bonus tip: Ask the question out loud and address either Source/Supreme God, or Gaia, or their higher self, or their true spirit guides. Each will have a different perspective although the answers will be similar overall, so only address one and not multiple at a time. The answers will be much clearer sometimes.
Drinking water is so important but not just to stay physically hydrated. Doing card readings or meditation, you will be channeling divine energy and that will actually be consuming water in your body. You may get hot or even sweat if energy is not moving properly or is overwhelming you. So drink water BEFORE doing readings as well as AFTER.
However, I do not recommend eating food right before doing card readings or even meditation. Or at least make sure you've digested already. Why?
This is because your body and your energy will be focused on digesting this food. When you're reading cards or meditating, you are connecting to the divine/higher self and you are channeling information, aka energy (information is held within this energy you're channeling).
In addition, your energy is interacting with the energy of whomever you're reading for. If you're still digesting food, that may lower your channeling ability, as in your senses, your sensitivities and such. Especially if this is for a paid reading, I want to be fully apt. That's my knowledge from having studied Pranic Healing with a master, so this is both experienced and learnt.
Of course, if you feel you need a snack, you should always follow that first. It's better to do a reading with food in, than with your stomach growling!
Personally, I never feel physically or emotionally drained from doing readings since I follow these little self-rules. That does not happen to me, unless I am already tired - in which case I will not read. It can be a lot sometimes yes, but only if the reading was particularly heavy or if I've done several long readings in a row - then I need a break to ground myself. But I won't ever feel drained. If you feel drained in any way, pay attention to what you are doing and in which state you're putting yourself into. If you're sitting for a long time, you might get tired physically so take care of yourself and take breaks (I know it's difficult when you're in the zone).
Always make sure you anchor yourself properly with Gaia/Mother Earth and with the Divine, so that you are not using your own energy and so that channelled energy moves freely. Imagine a pillar of white light/divine energy from heaven to earth and from earth to heaven - surrounding your body.