Left hand technique:
Where do I put my thumb when fingering chords?
Should I use it to press down the strings to create notes and chords?
There is a lot of discussion about thumb placement and Left hand position. Let me explain my point of view and goals in my suggestions to follow. First of all, putting aside the type of guitar, any amplification, and effects that might be used, the majority of your tone is a product of how you use your Left hand while playing. That may sound like a radical statement to many, but I believe it is true. Your Left hand, fingers, and their actions are major factors in tone, clarity, dynamics, and overall sound.
I always instruct beginning players to used a more "classical" approach to finger placement. There are many reasons why I do this. Here are a few of them. Most beginners are playing acoustic instruments. For the effort and in the long run, even playing an electric guitar, better sound is easier to produce using this technique. Better fingertip placement is created this way. When playing finger style guitar your first and second fingers will be more available than trying to "clutch" the neck using the thumb to create chords.
I understand that when playing an electric guitar this clutch method as I call it, is very useful and even efficient but it is far easier to learn the clutch method later than to try and get around the habit should you want to play more of a finger style technique.
So, for now, just trust me on this if you're beginning to train your Left hand. This may feel a little weird at first, maybe even a bit painful in your wrist but your are using muscles in ways you never have before. Just work at it and in the long run you will reap the benefits!
Ok, here we go!