Never practice these scales without a click. Start at a slow tempo (e.g., 60 BPM) and only increase the speed when you can play the pattern perfectly three times in a row.
To get the most out of this book, it is recommended to follow a structured, daily practice routine. a modern method for guitar scales larry baione pdf
As you play the G major scale, say "G, A, B, C..." This bridges the gap between physical memory and mental knowledge. Never practice these scales without a click