To wrap up discussion of normal practicing, when working on your songs, in the practice section (60%) you are trying to work on about as much of a song as you play through at a C+ grade in 60 seconds. The part(s) of the song you have no trouble with do not count in this total. As an example, if the song is 4 minutes long and you can do the first 2 minutes fairly well, you're focused on perfecting the next 60 seconds, and each time you perform the song, you'd do the first 3 minutes. The next day or several days later, you might be doing 3 minutes of the song well and now are focused on the last 60 seconds of the song. The 60 seconds of your daily work on a piece could be 2 pages or 4 measures depending on the difficulty. I hope you're all getting the idea. Now, a good plan on working this song or section of a song is perform the song (good parts + 60 seconds worth of hard parts) straight though, no stops, noting or remembering the mistakes and difficulties you're having. Remember that any place that gives you difficulties, even if it doesn't sound bad, is a potential mistake in a real performance. When you finish your performance, mark (circle, make a note on) all the places that are giving you trouble, even just a little trouble.
When you like a song, you actually only know only about 20% of the song. To perform it you must increase into the 80% and above.