Ok, I don't know if this is bad technique or not, but... Whenever i play fingerstyle, I always rest my thumb on the string below what I'm playing on. For example, if I'm plucking anything on the A string, my thumb rests on the E string. It doesn't seem to impede my playing any, but I'm still not sure if it's "bad technique" or not. If it is, how can I fix it?