The regular approach to developing psychic powers is to assume we have none and 'tack on' knowledge and skills until they appear.
Another, maybe more interesting approach is to assume we are omnipotent and start removing our defensive limitations until we achieve the desired psychic powers.
So how does unlocking psychic powers work?
First, you have to realize that you are not only your human self and that on some level you have the omnipotence of God. This is the easy part.
The hard part is introspection. Defensive limitations are there for a reason; they protect our consciousness from the blinding light of 'too much' and the black void of 'too little'. If you remove a limitation you are not ready to remove, you risk a permanent visit to the mental hospital or the graveyard.
The good news is that we are unaware in depth of these limitations, and it is difficult to remove something you don't know is there. Still, you have to be sure of your understanding and your choices and be willing to take the risk.
It's easy to unlock psychic powers - it can be much harder to prepare for accepting them.