Regarding fretting hand thumb position, I had always assumed that I was correct - or darn close to it. But I've recently discovered that my tp might not as mechanically sound as I had thought. On my 4, my natural inclination is to keep my thumb toward the G side of the neck (as opposed to the E side). And I tend to keep it fairly straight, using some of the pad but also some of the tip when making contact with the neck. I should add that I have odd thumbs - no backward bend like most people (I do not have "hitchhiker's thumbs" - they're nearly perfectly straight). So where is my thumb supposed to be? I'm trying to force myself to make contact in the middle of the back of the neck and to use more pad, but then my thumb moves toward the nut and this all feels awkward. But is this the correct way and I should continue to fight thru the temporary awkward stage? There are probably other threads on tp, but for some reason I want answers to my specific situation. Pics would be great. Thanks.