Timing is everything
Consider any opportunities you have to defer income to 2016. For example, you may be able to defer a year-end bonus, or delay the collection of business debts, rents, and payments for services. Doing so may allow you to put off paying tax on the income until next year. If there's a chance that you'll be in a lower income tax bracket next year, deferring income could mean paying less tax on the income as well.
Similarly, consider ways to accelerate deductions into 2015. If you itemize deductions, you might accelerate some deductible expenses like medical expenses, qualifying interest, or state and local taxes by making payments before year-end. Or, you might consider making next year's charitable contribution this year instead.