Alternate Picking is the most difficult picking technique, therefore a long practice is required. While the left hand is holding and releasing strings, the right hand continuously pick up and down. Actually the right hand plays more precisely than the left one — it doesn’t matter when the strings are released but pressed. Therefore it is difficult to apply a professional play to the right hand. Finally both hands have to interplay.

Independent if you are a beginner or immanent, this lesson will help you improving your alternate picking. Make sure you have warmed up your fingers before continue.

Use a drum beat machine and set the BPM to 100 — beginner should set to 60. Hold the D string at fret 12. Start playing and pick 16/16, 4 notes per beat, 4×4=16. When necessary change the BPM slower or faster.

Then play following tab (16/16 notes):
E||——————————————————————————————————–….
B||——————————————————————————————————–….
G||——————————————————————————————————–….
D||——————————————————————————————————-3…
A||—————————————————-3-3-3-3-4-4-4-4-5-5-5-5-6-6-6-6–….
E||3-3-3-3-4-4-4-4-5-5-5-5-6-6-6-6——————————————————….

Continue it. Pick down and up, down and up on all 6 strings.

The pattern is 3-4-5-6, every note played 4 times (4×4=16). It’s unnecessary to play this for many hours, 10-20 minutes every day is fine and already will improve your play. Actually the major improvement is, when you move between the strings.

• More patterns. All notes played 4 times.
  12-11-10-9
  10-9-11-12
  11-12-9-10
  4-6-3-5
  3-5-4-6
  5-7-6-4
  6-4-5-7
• Play the aforementioned patters again; however now you play every note twice and still 16/16 (9-9-10-10-11-11-12-12) 
• Finally play every note once and still 16/16 (9-10-11-12).
• Play all exercises again, but change your picking: up-pick, down-pick, up-pick, down-pick, …
• Combine it with lesson Guitar 180° (optional)

A few recommendations at the end: 

• I guess your dream is to play fast. This exercise helps, but you have to practice slow. Increase the BPM slowly after time. Find your weakness and work on it. For instance, your little finger is slow, then practice it.
• Maybe you practiced for a long time and don’t see the result you have hoped for. Practice slow, at least five minutes, and finally play fast once or twice. You’ll probably see the difference.
• Research TABs and memorize songs. In order to memorize an entire song, you have to play one by one and slow. It will improve your alternate picking and avoid being bored.
• Close your eyes while you play. Imagine what your hand is playing and look at your finger movements in mind before you play in reality.

Enjoy!