Neckstraps.Yes and NO. A neckstrap for this purpose is the traditional way but it is recommendable only under particular conditions. A shoulder strap (or even better two of them) is a much better solution. Hanging things on the neck causes unsuitable load on the part of the body which is most vulnerable for muscular strain. If holding the instrument with forearms horisontal the resulting force acting on the neck will be 1,4 times or more x the weight of the instrument - not purposeful!IF a neckstrap is used at all the instrument should be hanging low with the straps vertical to reduce the load (= the weight of the instrument).A shoulder straps thus is preferable.
The best way to attach the strap to the instrument is by means of an intermediate strap fastened to two endbolts at each side of the instrument and the shoulder- ( or neck-) strap in turn attached to the intermediate strap by clips ( like those used for braces/suspenders) at optional location either side. ( by this method the angle at which the instrument balances may be perfectly adjusted).