Let's put some light in this ...
Offshore accounts doesn't necessary means tax heaven ... Offshore is basically doing business in
OTHER country that you(or your company) reside.
What interests us here is tax heaven countries where the taxes are very low or a fixed low rate..
Example:
I get a cargo with clothes and I pay $50K to the merchant. Then I resell the clothes to 3 shopping malls getting $75K .. After Expenses I get a $25K pure profit. Here in my country I have to pay a 16% to the gov.. Thats
16% * $25K = 4K to the gov .. Profit for me only $21K.
Using an offshore company
Get a cargo with clothes and I pay $50K to the merchant. I resell the clothes to 3shoppingmalls getting $75 but they will pay the money to my bank account in Panama (Tax heaven)...Here the taxes are only $200 flat fee annually . After expenses I get a $24.800 pure profit nothing to the gov

In first case I cash in $21K and second $24.800
There are more ways like fake expenses etcetc.
Now I hope you get it why tax heavens are useful
Another strong point is anonymity. Before getting a bank account or company in an tax heaven you need to make sure that country/bank doesn't have a special contract with your country to exchange infos .. If it does than is not for you...
Also you should know that tax heavens have special regulations for doing business in that country.For example if you set up a company in New Zeeland and you're doing business in NZ you need to pay taxes like a regular NZ company..if you're doing it outside no special taxes
Another aspect:
Different tax plans for activities.... If let's say you want to start an online casino and you incorporate it in Panama you have to deposit in their banks a huge amount as guarantee (1 million $ If i remember well) but in Costa Rica no special deposit is required.. The license is only around $1.5K
Internet banking
You should do some research when you choose a bank account in this countries as you need INTERNET BANKING (to manage the account from the comfort of your home) and DEBIT CARDS ( to get out the funds) or WIRE TRANSFER Fees. I was pretty happy with ex-URSS countries (Latvia) and Seychells banks
Hope this post helped..if you have questions I'll be glad to help you
bluey .. Vanuatu is good for getting car new license plates. I think there is the only jurisdiction where you can enlist your car without its presence there.. All your speed tickets will go to Vanuatu ..pretty cool huh