In order to get an offshore account as a tax haven you willneed tostart or buy a business that is registered to an offshore address. This can be set up for you in a matter of 3-5 weeks by specialist companies but it isn't cheap - typically anything from 500 - 1500+ depending on the business nature and the country.
The only sure fire way of hiding it is deal in cash and store it under the matress , that is until the missus finds it lol
Don't know too much about the WFTC though and if I did it wouldnt be wise to discuss it here 
Never had a problem with excess money tho' with a wife and two teenage daughters lol