Everyone receives their psychic information differently. Many of the signs are subtle; we've learned to ignore things such as ringing in our ears because it mostly seems like an annoyance when it could actually be psychic information trying to get through.
Persistent ringing in the ears, often presenting as a high pitched frequency, can be a sign of psychic information. I've had mine all my life, and I learned to ignore it because it was just always there as background noise. I recommend this technique in some of my classes if you've always had this as I have: use it as a meditation focus. Instead of ignoring it, clear your mind and then focus on it. If your mind drifts, return your focus to it. Start with short five minute meditations and work your way up. Release expectations but be open to anything. It can be eye-opening (or ear-opening) for many to try this.
I am also a medium. I hear from and communicate with dead people. One of my signs this is about to occur is I feel pressure in my ears. It feels kind of like the pressure you feel as you climb to elevation, but it's fuzzier. It's difficult to describe. When I feel the ear pressure, I know information or communication is forthcoming, so if I'm available in the moment, I stop what I'm doing and focus on it.
Another sensation I get just before I receive psychic information or when a spirit is present and wants to communicate is through my sense of smell. I smell something similar to ozone. There's an edge to the scent that smells similar to what the air smells like just before a thunderstorm or a lightning strike.
Other signs might include sensations in my body that don't make sense. I ask, "Is this mine?" If it isn't, then I focus in on that to see what information I receive. For example, I may feel as if my airway is constricted (although I can still breathe - it feels like a tightness in my throat), I may have a random ache or pain, I may feel sudden onset of dizziness, or similar. This is very common with empaths, and it's important that, while we learn to listen to the information, we also disassociate from ourselves so we don't allow it to stick in us and become dis-ease. If we believe those sensations are ours, we often accidentally embody them until we become ill in some way. I find empaths often have a lot of things such as migraines, random aches and pains, fibromyalgia, autoimmune disease, and other symptoms of illnesses that are often undiagnosable when you go to the doctor.
While I receive the physical symptoms as information almost constantly when I'm in large groups of people (I'm picking up everyone else's aches and pains), I do find this version of psychic information incredibly helpful in my energy healing practices because it tells me what my healing partner feels. I also have a technique I use when they arise so I don't embody the symptoms. I ask, "Is this mine?" Usually it isn't. So I say, "Thank you for the information," and then I push the sensation down my center column, down my legs, out through my feet, and into the earth.
Other sensations that could indicate possible psychic information include having persistent thoughts that suddenly appear in your head and don't change or go away (again, ask yourself, "Is this mine?"), emotions unrelated to my current experience, seeing things out of the corners of your eyes, having other visual disturbances such as seeing a shimmering similar to heatwaves, having strange tastes in your mouth that don't make sense in the current context such as tasting cigarettes or alcohol when you don't smoke or drink, or any other sensations that simply feel out of place.
If you are experiencing a lot of physical sensations like I described above, it's important you make sure you have them checked out medically first to make sure there isn't a medical reason for them. Sometimes there is, and I'd hate to have you miss a medical condition because you believe your symptoms are psychic. However, after receiving the medical all-clear, then pay attention to the symptoms as they arise. Ask yourself, "What is this trying to tell me?" If you have time, focus on the sensation for a moment and see what arises. Do you see flashes of images, receive persistent thoughts, or notice vibrations, for instance. Pay attention. Keep a journal and note what the sensation seems to be telling you. Then, say "thank you" and then "Not mine" and release it so it isn't stuck in you.
It's important you learn to stop ignoring your signals, trust the information you receive, and then release it. This is how you build healthy psychic practices while still protecting your own well-being.