Be honest. If it's a gift, or a sample, or documents, declare it as such and provide the actual value of the item(s). There should be no duty or taxes incurred by the recipient.
If it's not a gift, a sample, or documents, then chances are it is merchandise. Declare it as such and provide the replacement value of the merchandise, not the resale or retail value.
Of course, you could just lie, but being completely honest is not all that hard. You also sleep better!