Don't, per this article.
"Large gifts that shrink an estate for tax purposes no longer make sense for many people now that the federal government taxes only estates larger than $5.34 million, or $10.68 million for couples.
With that threshold—which adjusts for inflation and which Congress has called permanent—so high, many financial advisers recommend that their clients wait until they die to give their assets away.
The inheritance approach can lower capital-gains taxes if the heirs then sell those assets."
New Tax Rules Give the Wealthy a Reason to Hoard Assets - WSJ.com