Hi Lars,
Welcome to iCraft!
Our Shipping Profiles are not Zip Code specific. You can set them up by Country and have one International profile.
For light items, like small jewelry items, it sometimes makes sense to add shipping cost to price and offer Free Delivery, but that usually doesn't work for larger items. Not sure if that's what your were asking for.
I'd say, it's best to create 3 Shipping Profiles - one for US, one for Canada and one for Shipping Worldwide.