Each time, before you intercede, be quiet first, and worship God in His glory. Think of what He can do, and how He delights to hear the prayers of His redeemed people. Think of your place and privilege in Christ, and expect great things!
The doctor, if he forgets he is only the assistant to nature and zealously takes over the stage, may so add to what nature is already doing well that he actually throws the patient into shock by the vigour he adds to nature's forces.