I was told by a really good guitarist that the best way to improve form was to choose a song, isolate particular difficulties, and base your schedule on variations on what you have difficulties with.

The example he gave was with Pantera's Flood solo, where he basically practised bends and pentatonics for a week, the went back to the solo and nailed it in a couple of attempts.

Now this dude has be playing for about 8 years, so maybe he is just at most parts of the song anyway and didn't require practise on the other components.

Basically, as a beginner, am i best to start off learning "a little bit of this, a little bit of that", or should i focus on one activity to a moderate degree of competence before progressing to another?