Capital losses of up to $3K/year. Sucks to take a loss, but if you have some losers get rid of them and use the deduction.
Talk to your employer if they are flexible about you taking more benefits and less taxable income. Car/mileage, cell phone, insurances, and even deferred compensation. Check out
this thread of mine from 2 months ago. It's not something most people can do, but it's going to save me a shitload of taxes this year so it's worth mentioning.
Have you considered switching to part-time or reduced time? Maybe 4 days a week for 80% of the pay? Might be a good test run on your way into ER.
Be careful not to let that taxable income get too high. I don't know exactly where you stand based on the facts given, but there are a lot of phaseouts north of $125K. In 2013 they added the additional medicare taxes for income north of $250K, and they started phasing out exemptions and limiting total itemized deductions as well. I don't remember the threshold for those phaseouts, but somewhere in that range (150K-250K) as well I think.
Good luck. Let us know if you learn any other tricks.