When you try to do with the mind, as your thought and imagination engaged, then doubt comes. When all your energies are engaged with the future outcome, your ego steps in and we lose consciousness and are no longer in the moment, focus goes.
If you allow your mind to go silent and just go with the flow of thing you are doing, if let go of thinking about the outcome and result, you let the pressure go, your ego is no longer there, so you are not fearing failure, or ridicule or anything. The doing will flow through you and will happen without any resistance or negative thoughts.
The joy of the doing comes and what you are doing just unfolds with ease.