The MadFIentist has a number of topics on tax optimization and (legal) avoidance/reduction.
His "archives" include a section called "Tax Avoidance" with the following topics (as of June 2015, he adds more all the time):
Retire Even Earlier Without Earning More or Spending Less
Traditional IRA vs. Roth IRA – The Final Battle
The Ultimate Retirement Account
Lab Rat and Assumptions
Triple Value of Income
How to Hack Your HSA
Roth IRA Horse Race
After-Tax Contributions and a Surprise Gift from the IRShttp://www.madfientist.com/archives/
They are well worth checking out!