Concentrating really well on things you do, not suprisingly, helps a lot in succeeding. It is not the only factor that makes or breaks things but for example in sports you can often try something many times mediocrely, then concentrate once well, and get much better results. A lot of training is needed to learn things but you can get better faster if you pay attention.
This applies also to really simple every day tasks. Until I was 25 years old I thought that cutting fingernails from my right hand was hard. Then, for once, I analyzed what I did with scissors in right hand and compared it to what I did with scissors on left hand. It turned out that when I was cutting my left hand nails I turned the finger and kept the scissors stationary. When cutting my right hand nails I was trying to turn the scissors. After that I have always kept the scissors stationary and got equally good results on both hands. Pay attention to what you are doing.