When I give a Priesthood blessing I go into it expecting to give comfort - NOT healing or saying anything uniquely profound. I try to be open to whatever might come out of my mouth, but I don't intend to perform miracles.
Call it what you will, but I have found that doing so "works" or is "successful" 100% of the time - since I am open to those times where the Lord chooses to speak through me. Of the hundreds of blessings I have given, there have been hundreds that offered comfort and counsel, a dozen or so that mentioned healing that might or might not have been remarkable and three that have blown me away as I thought afterward about what came out of my mouth.
It was worth giving comfort in the hundreds just for the comfort's sake - but it absolutely was worth it to have those three experiences.
I think life is like that in a lot of ways.