How And Why To Practice Scales
One of the standard ways of developing your speed and technique is to practice scales with a metronome and gradually increase the speed. Beginners should start very, very slowly, and not aim to build up the speed too much - but simply to get used to playing in time with a metronome.
A beginner will probably be focussed on just playing with the metronome but Intermediate players should be really focussed on the synchronization between the hands - that really is the key here. As you get faster the synchronization needs to be better and better and you'll find this helps even when you play slowly!
How To Do It
1. I would recommend starting with Pattern 1 of the major scale (in G Major, start with your second finger on the 6th string root, at 3rd fret). See the Major Scale Pattern 1 if you are unsure about this. Remember that most of your early work with scales should be just around Pattern 1 until you can use it well! Make certain you can play the scale perfectly without thinking much about it before you even think about working on this!
2. If you are new to technique exercises then you should start at something like 1 note per metronome click at around 60bpm (Beats Per Minute). Better to start very slowly and get it right. Aim for clarity in every note, don't let any notes smudge or be muffled. And make sure that you are using your fingertips.
3. Aim to get your note well synchronised with the metronome click, don't let yourself rush. Rushing is a common problem for beginners so try and relax and play with it. Don't fight against the click of the metronome - you won't win! It should be your pacesetter 'running' by your side - you neither follow or anticipate it
4. Try and tap your foot with the metronome too to help develop your internal metronome.
5. Only when you can do a scale PERFECTLY 4 times consecutively (in a row) should you move the speed up. You might want to start by moving the metronome up by 10bpm at a time to start but as you get closer to your maximum speed you should slow the increments, maybe just going up by 5 or even 2 bpm at a time.
6. Once you get to 160bpm, move on to 2 notes per click at 80bpm (eighth notes). This means that you will play one note with the click and one note in-between. This is great practice for your alternate picking too because the down pick will always be with the beat and the up pick will be between the clicks!
7. Once you get up to 160bpm again, then move to doing 4 notes per metronome click. This is called playing 16th notes.
8. Get up to a reasonable speed in Pattern 1 (like 16th notes at 120bpm) before moving onto any other scale positions. A really fast speed is 4 notes per metronome click at 160bpm. A good target speed for general playing is 140bpm, only speed metal rockers will need to play much faster than that.
9. Make sure that you monitor your technique and that you keep as relaxed as possible. Tension is the enemy. I would suggest getting a private lesson or two to check you are picking correctly and that your hand position is good. Remember not to let your wrist bend too much. Ask around among good players and get a teacher recommended.
10. Another common issue is the angle of the pick, it should be at an angle of around 10-15 degrees to the string. Too flat on and it's likely to get tangled up in the strings.
Unless you're doing big practice sessions (over 2 hours a day) you probably don't need to do more than 5 Minutes a day of this. I still revisit it from time to time but I'm lazy with picking practice to be honest - I find it a bit tiresome and I'd rather be doing something more creative!
The most important thing to remember is to do it accurately and clearly - without this, your scales will sound rubbish! Take your time, do it properly and when you play fast it will be clear and sound totally cool. I know how exciting it is to play fast and it is a lot of fun, just don't push yourself further than you are ready to go!