Linda Stern is a freelance writer. Any opinions in the column are hers. You can follow Linda Stern's financial notes on Twitter at http://www.twitter.com/lindastern

WASHINGTON, April 14 - Don't tuck those tax forms away just yet. Take a minute, first, to look them over for insights about how you are managing your financial life. A careful read of your 1040 can point you to big mistakes that can cost you big bucks all year long.

Check out these line items on your return to make sure you're not making one of the five biggest financial blunders.

-- You are giving Uncle Sam a free loan. Maybe you liked getting a big refund, but that's just a sign that you had too much withheld from your paycheck to pay for taxes. The Treasury isn't paying any interest on the money it's been holding for you all year long. Here's how to fix this: Fill out a new W-4 form at work, to cut the amount of taxes withheld from your paycheck by roughly the amount of refund you got this year.

Arrange to have that amount automatically deposited in a savings account with every paycheck. Next April, if you owe taxes, pay them out of that account. If not, consider the savings, plus any accumulated interest, a bonus. You can invest it for bigger gains down the road, use it to pay down lingering debts, or blow it on something fun.

-- You aren't saving for retirement. Did your return include adjustments for your contributions to a self-employment retirement plan or Individual Retirement Account or a health savings account? If none of the above, there's a chance you aren't taking full advantage of the many tax breaks for retirement savings. You should have at least maxed out on your 401(k) contributions and stashed money in a nondeductible Roth IRA? If the answer to that is none of the above, either, you can fix it by starting with your work 401(k), and learning enough about the various types of IRAs to choose the best one for you for a 2010 deduction.

-- You're not keeping track of your generosity. Do you think you ended up low-balling your deduction for charitable gifts because you didn't have receipts, or couldn't remember how many old coats, books, and lamps you gave away? Perhaps you give small amounts of money to too many different charitable organizations to remember. Set up a record-keeping plan right now, either on your own or by using the free online program offered by TurboTax called It's Deductible Online (http://turbotax.intuit.com/personal-taxes/itsdeductible/index.jsp). Next year, you'll be able to just insert a number and get the biggest possible deduction.

-- You're not staying on top of losers. If you had big capital gains in 2009, they should have been offset by the carry-over of big losses you took in 2008, when the stock market tanked. Be aggressive about selling stocks and shares of mutual funds when prices drop -- you can even choose which mutual fund shares to sell if you've bought some at higher prices than others. Don't repurchase the same investment for at least a month. Then you can use those losses to offset other 2010 income. Furthermore, your mutual fund can carry forward losses, too. So if the fund you own distributed a big taxable gain to you in 2009, even if you didn't sell it, your fund manager may not be handling this issue right either. Consider switching to a more tax-efficient fund.

-- You overpaid your tax preparer. If you're hiring someone else to do your taxes, and they didn't go over all of these points with you, you're not getting your money's worth. Furthermore, if you have a simple tax return -- say you don't have a side business or a lot of investments -- you really should take a crack at doing it yourself next year. That way you can learn the most about how your tax picture comes together, and you might be able to save some money. You can still get it reviewed by a pro after you are done.

(editing by Gunna Dickson)

Twitter