Raising arms like Sam suggests can be done without rotation, but you need good rotator cuffs to do it. If your rotator cuff is torn (as is the case with many people) then forget it.

Assuming the Poser Position (arms out) IMHO does help with modeling.  DaVinci seemed to like it.

I do recall a trend some years ago to use 45 degree angle down.  Probably a good trend but it was short lived.