When my brother was learning to play the dobro, he drove everybody in the house crazy. He would play one phrase, over and over and over and over. My father used to say, "Joe, play a whole song. Stop playing those little pieces."
Well, my brother Joe turned out to be a killer on the dobro. By repeating licks (way past everybody else's endurance), he put all those pieces in his fingers and brain and made himself into a real player. There's an important lesson in this about the value of practice and repetition.
You have to isolate the places that give you trouble and play them over and over.
I used to play tunes from beginning to end. There would be places I would mess up, places I would slow down, but I'd trudge on to the end. Sitting there at home, I could play the tune (sort of), but I could never play it in public, because those places I would slow down or mess up would always stop me cold. Just as a chain is only as strong as the weakest link, you're only as good in a piece of music as the part you play the slowest, or the part you mess up.
Here's an example. There's a place in the B-part to "Bill Cheatham" that always makes me stumble. Happened again the other night at a bluegrass jam. It involves the little finger (of course) and a certain shift. What I must do if I want to master this and be able to really play it is to isolate the part that gives me trouble and repeat it, over and over and over, like my brother Joe those many years ago. Do it with a metronome (see practice tip #3!). Keep doing it. Do it until you can play it ten times in a row without messing up. Then put it back in the song and do it some more. Start a little before the bad place, then play on past it and start over.
I know this to be true for all kinds of music. If you're reading music (or tab) , you should mark the hard places so you'll remember what makes you stumble. Then go back to those places and clean them up so that you don't stumble. Over and over and over and over and over.
Enough! I'm going to quit typing and work on that darn pinky move in "Bill Cheatham"! I've got to get that thing in my brain and my fingers.