Check out Mitt Romney's 2010 tax return and learn how he does it. The most important lesson I learned in perusing his return (besides the significance of sheltering your $$ outside of the USA) is the immediate impact of targeted charitable contributions. In my professional opinion the absolute best way to reduce your tax liability is to make charitable donations of money or property. Also you can try to:

Avoid salary, wagesand tips if you can. Instead generate income from long-term capital gains

Avoid Muni-bond interest. It triggers Alternative Minimum Tax (AMT) making this investment vehicle laughable at best for the truly wealthy

Pursue Qualified dividends. They are essentially ordinary dividends that meet the requirements to be taxed as net capital gains. Check out Publication 550, Investment Income and Expenses

Avoid the home-office deduction. It offers a small tax benefit requiring large tax prep effort (aka $$). Usually not worth the time and effort.

Itemizing deductions is probably not worth the personal disclosure required

Beware that capital gains and dividends can also trigger the AMT

Offshore investments can be perceived as abusive because they rob the US Treasury of much needed tax revenue. Basically the US Tax Code encourages the wealthy to invest OUTSIDE OF THE UNITED STATES which is so backwards it makes my head spin.