Here they are, in no particular order:

1. Increase the amount you will set aside in your employer's health flexible spending account (FSA) for 2012 if you set aside too little this year.
   • Remember, you can no longer set aside amounts to get tax-free reimbursements for over-the-counter drugs such as aspirin or antacids.
2. If you become eligible to make health savings account (HSA) contributions in December of this year, you can make a full year's worth of deductible HSA contributions for 2011.
3. Realize losses on stock while substantially preserving your investment position.
   • For example, you can sell the original holding then buy back the same securities at least 31 days later. It may be wise to meet with your investment advisory team to discuss year-end trades.
     
4. Postpone income until 2012 and accelerate deductions into 2011 to lower your tax bill for this year. This may enable you to claim larger deductions, credits, and other tax breaks for 2011 that are phased out over varying levels of adjusted gross income (AGI).
   • These include child tax credits, higher education tax credits, the above-the-line deduction for higher education expenses, and deductions for student loan interest.
   • Postponing income is also desirable for those who anticipate being in a lower tax bracket next year due to a change in financial circumstances. Note, however, that in some cases it may be more beneficial to accelerate income into 2011.
5. If you believe a Roth IRA is more beneficial for you than a Traditional IRA and want to remain invested in the financial markets for the long term, consider converting your Traditional IRA money invested in beaten-down stocks or mutual funds into a Roth IRA if you're eligible to do so.
   • Keep in mind that such a conversation will increase your AGI for 2011.
6. If you converted assets in a Traditional IRA to a Roth IRA earlier in the year, the assets in the Roth IRA account may have declined in value. If you leave things as they are, you may end up paying more tax than necessary.
   • You can recharacterize the rollover [or conversion, that is] by transferring the converted amount - plus earnings or minus losses - from the Roth IRA back to a Traditional IRA via a trustee-to-trustee transfer. You can later reconvert to a Roth IRA.
7. Consider using a credit card to prepay expenses that can generate deductions for this year. 
8. If you expect to owe state and local income tax when you file your return next year, consider asking your employer to increase withholding of state and local taxes, or you can pay an estimated amount of state and local taxes before year-end to pull the deduction of those taxes into 2011.
   • Be careful that doing so won't create an alternative maximum tax (AMT) problem.
9. Take an eligible rollover distribution from a qualified retirement plan before the end of 2011 if you are facing a penalty for underpayment of estimated tax and the increased withholding option is either unavailable or insufficient to address the problem.
   • Income tax will be withheld from the distribution and will be applied toward taxes owed for 2011. You can then rollover the gross amount of the distribution in a timely manner as increased by the amount of withheld tax to a Traditional IRA.
   • No part of the distribution will be includable in income for 2011, but the withheld tax will be applied pro rata over the entire 2011 tax year to reduce previous underpayment of estimated tax.
10. Estimate the effect of any year-end planning on an alternative minimum tax (AMT) for 2011, keeping in mind that many tax breaks allowed for purposes of calculating regular taxes are disallowed for AMT purposes.
    • These include the deduction for state property taxes on your residence, state income tax [or state sales tax, if you elect this deduction option], miscellaneous itemized deductions, and personal exemption deductions.
    • Other deductions, such as medical expenses, are calculated in a more restrictive way for AMT purposes than for regular tax purposes. As a result, deductions should not be accelerated in all instances.
11. Accelerate "big ticket" purchases into 2011 to assure a deduction for sales tax on the purchases if you elect to claim state and local general sales tax instead of state and local income tax deduction.
    • Unless Congress acts, this election will not be available after 2011.
12. If you are a homeowner, consider energy-saving improvements to your residence such as putting in extra insulation, installing energy-saving windows or energy-efficient heaters or air conditioners.
    • You may qualify for a tax credit if the assets are installed in your home before 2012.
13. Consider prepaying expenses for higher education if doing so will increase your deduction for qualified higher education expenses. 
    • Unless Congress extends it, the up-to-$4,000 above-the-line deduction for qualified higher education expenses will not be available after 2011.
    • Generally, the deduction is allowed for qualified education expenses paid in 2011 in connection with enrollment at an institution of higher education during 2011 or for an academic period beginning in 2011 or the first 3 months of 2012.
14. You might want to pay any contested taxes in order to deduct them in 2011. You can then continue to contest them in 2012.
15. You may want to settle an insurance or damage claim in order to maximize your casualty loss deduction this year.
16. If you are age 70 ½ or older, own IRAs, and are thinking of making a charitable gift, consider arranging for the gift to be made directly by the IRA trustee. 
    • Such a transfer, if made before year-end, can achieve important tax savings.
17. Take required minimum distributions (RMDs) from your IRA of 401(k) plan (or other employer-sponsored retirement plan) if you have reached age 70 ½.
    • Failure to take a required withdrawal can result in a penalty of 50% of the RMD amount not withdrawn.
    • If you turned age 70 ½ in 2011, you can delay the first required distribution to 2012. Just remember, you will have to take a double distribution in 2012 - the amount required for 2011 plus the amount required for 2012.
    • It might be beneficial to take both distributions in 2012 if you will be in a substantially lower tax bracket next year, if - say - you plan to retire late this year. 
18. Think twice before delaying 2011 distributions to 2012.
    • Bunching income into 2012 might push you into a higher tax bracket or have a detrimental impact on various income tax deductions reduced at higher income levels.
19. Take advantage of gifts sheltered by the annual gift tax exclusion before the end of the year and thereby save gift and estate taxes.
    • You are eligible to give $13,000 in 2011 to each of an unlimited number of individuals but you can't carry over unused exclusions from one year to the next.
    • The transfers may also save family income taxes where income-earning property is given to family members in lower income tax brackets who are not subject to the kiddie tax.