I'm a beginning bass player with a couple months' lessons under my belt. I haven't gotten far along enough yet to solidify a playing style, so I'm still able to change my habits if I want to. I was wondering what the pros and cons are of the various places you can rest your thumb while playing bass and how they affect playstyle (if at all). I'm going to divide my question into sections about what I've heard and what I currently do to make this a little cleaner to read.
I'm currently taking lessons and my teacher told me to start out resting my thumb on the pickup, which seems to be a fairly accepted standard. Keeping my thumb upright seemed to help me keep my picking technique cleaner in regards to holding my fingers straight.
I've been perusing a lot of information online, and one thing that I came across some months ago (I can't find the link, apologies) was someone saying that in the long run, this can be detrimental to your electronics. He said that over time, the sweat and oil from your skin can end up messing up the electronics in the pickup which would result in them needing replaced. However, I don't have enough knowledge or experience to be able to make a judgment call on the validity of this statement. Has this ever happened to anyone? Is it really a valid concern?
I've recently started resting my thumb on my E string while playing. I lowered the action on my bass, so it helps to keep it dampened. Should I be moving my thumb down to the A string when I pluck the lower strings? Is it okay to keep it on the E or should I go back to the pickup?
I've also read online that some people mount separate thumbrests on their guitars. What are the advantages/disadvantages of this?
Basically, what the advantages/disadvantages of these methods (or any others I have missed)? Is there any accepted "right/proper" standard? Are certain methods of play used more in certain playstyles (i.e. blues/metal/jazz/etc.)?