Clairsentience is when yor body picks up intuitive information and spiritual energies from other non physical sources. It's your gut instinct and tends to be very simple in it's guidance. The body seems to speak in very simple "language" such as: good/bad, I like/I don't like, this feels right/this doesn't feel right, and so on. In fact the body is so direct and black and white in its guidance that it is easy to ignore. It actually takes quite a well grounded discipline to be in tune with your body's messages to the point that you choose not to ignore it but simply flow with it. I think that is because in most societies we are apart of systems where pushing the body is encouraged such as working rather then not sleeping, dealing with large qualities of stress without stopping, and basically being more in the mind then the body.
When you are reading cards it is important to be mindful of how your body, your stomach, and breathing react to the cards that are pulled. Your body will respond with hesitation when reversed and "negative" cards come up, not because the cards are bad but because your survival instinct is well aware of the metaphor, "Don't kill the messenger." Your body knows that the client may not be open to hearing something they don't want to hear and that brings up the possibility of being attacked or criticized for being a bad reader. If you are hesitant to bring up some "bad news message" because a card came up with some ominous symbols then it will effect the quality of the reading. And every reader knows that when reversed cards come up (or cards with ominous symbols) the client tends to zero in on those ones first so you might also be dealing with feeling their fears of "bad news."
The first thing I do when I look at cards in a reading is I breathe and mentally tell my body that red flag cards in the spread are nothing to be afraid of. Sometimes I visualize white light surrounding my solar plexus chakra so that my body's guidance doesn't shut down. As I tell my stomach to relax and trust that the message is what is needed to be expressed I've found that this helps me to keep the clairsentient channels open; and in this way I don't end up sugar coating anything.
Being clairsentient leaves you vulnerable to other peoples resistance to the truth as you are seeing it through the cards. If your body takes on energy easily, especially if you have yet to develop energy protection techniques that work for you, then you could find yourself feeling drained or anxious when you are reading. When you sense that your stomach is getting tight or that your nerves are getting agitated it's ok to stop for a moment, take a deep breath, mentally tell your body that everything is ok, and then keep going.