I usualy will use US post office service to mail package to Taiwan.
For iTouch, it is a small size with less weight. Thus it can be easily wrapped.
(a) You need to use the bubble (plastic wrapper) to pretect your iTouch. You can buy it at post -office as well (usually less than $5) The post office isl not responsible for damage.
(b)You should use Express mail that you can track where the package been send, in this way it will not be lost easily. You will use the envolope from US post office (free) and the cost of mailing express mail is about $19.95 if you do not want to add the cost of insurance (most of people will not)
(c) you will be asked to fill a custom form. You should indicate it is a used iTouch as a gift. Do not check for business. 99% that you will not be taxed if you only mail 1 iTouch.