Greetings, GeccoMorgan, and welcome. You asked:

<<After maxing out one's 401K and utilizing the Roth IRA, are there any additional steps one can take to shelter (fully or at least party) income from short term taxes if the money is earmarked for retirement or long term investing?>>

The only thing left is an after-tax annuity. That's appropriate if your sole goal is to shelter any earnings from income taxes until you retire; however, in general they make a poor substitute for the purposes of maximizing your savings. If the latter is really your goal, then stick with a taxable account within which you use stocks to maximize growth and minimize dividends. When you sell, the growth gets taxed at much lower capital gains rates. Chances are far better that you'll end up with more money that way then you would in an annuity after you start withdrawals that get taxed at ordinary income tax rates.

Regards..Pixy