Belief, Trying and Doing
To believe you are able to do a task is the first step in actually being able to achieve it.
With any psychic, hybrid, or magick technique you MUST believe in your ability to complete it.
If you have any doubt it is most likely that the technique you attempt will fail.
Key #1: Believe in yourself.
When a person says, "I will try," they are expressing the sentiment that they wish to achieve a certain goal, but it also shows there is doubt in their ability to complete it successfully.
Trying to do something is the same as not believing you are able to achieve your goal.
If you try, then you will fail.
Key #2: "Do, or do not, there is no try." (Yoda)
Doing a technique and failing at it is not the same as trying it.
If you fail at a technique then that simply means you have something wrong somewhere and you should change what you are doing slightly.
When you believe in yourself and do a technique, if the conditions are right, you will succeed.
Key #3: Do it and succeed.