For me, it didn’t happen until I stopped trying so hard, and by trying, I mean over ten years of practice with little to no result.
I have a shield around me that was put up by the Greater Me, and it effectively cuts me off from a lot of spiritual access.
At first, once I learned about the shield, I was running around, trying to bring it down, until a friend channeled Belial on my behalf, and he said that the shield was protecting me from some very nasty stuff that would be far worse for me than the insensitivity caused by the shield.
Belial also said something that has stayed with me ever since. He said, “Spirit cannot be rushed, and things will open in their own time.”
In other words, you cannot force it to happen. You do the meditations and the rituals, and your Greater Self judges when you are ready for more.
Once I realized that and let go of my need to have experiences like those described on this forum, things started to happen for me rather quickly. My clairaudience kicked in and suddenly I was hearing voices from around me. My clairvoyance is coming much slower, but it is in progress.
Always remember, you do not need to see or hear spirits to be successful with magick.