TOPIC: Most Productive way to spend limited practice time

If I can only manage a short practice each day what is the best way to spend that 15 minutes? What will have the most impact?

Playing scales and arpeggios....

Also, learn the scales in different positions on the neck and combine different positions as you go. I started playing the G major scale in the first position going up two octaves then, I played the first 3 notes (G, A, on the 6th string and took it from there (2nd position). I,ve begun to see more clearly the whole step/ half step relevancy on the neck because of that. When changing positions, use open strings when possible to assist the move without missing a beat. Try playing a scale on the same string up and down. It'll help you understand when to change hand position.