Still searching for that last-minute eureka on your 1040? Perhaps you’ll find it here. Trim your taxable income with these strategies, and don’t miss frequently overlooked deductions.

Look for losses. If you took a hit in the market in 2007 or even if you switched investments within a fund family at a loss, you can spin the pain into tax gold. First you must use losses to offset capital gains. Then you can deduct another $3,000 worth against ordinary income. What’s left carries over to later tax years. So make sure you don’t have any leftover losses from, say, a bad bet on GM in 2005.

Pad your retirement. You can fund an IRA for 2007 until April 15 (the max is $4,000; $5,000 if you were 50 as of Jan. 1). And don’t assume you earn too much to write it off. Even if you and your spouse have retirement plans at work, you can deduct part of your contribution if your modified adjusted gross income (AGI) is below $103,000. For a full deduction, your modified AGI must be $83,000 or less.

Itemize. Some 63% of taxpayers don’t itemize – at their financial peril. A 2002 Government Accountability Office report found that filers who should have itemized but didn’t paid $438 extra on average.

Are you stuck paying the AMT?

Honest answer? Probably not. Designed to ensure that the super-wealthy don’t get away with paying nothing, this parallel tax system increasingly snags middle- and upper-middle-income families because Congress never indexed the AMT to inflation; as incomes rise over time, so does the number of people stuck paying tax under the AMT.

Late last year Congress passed a “patch” that exempts more income from the AMT, but the levy will still trap some 3.5 million filers this year, according to the Tax Policy Center. If you use tax software, click yes on the window that pops up asking if you want an update. That will make sure you have the correct AMT rules.

While the AMT snare is hard to escape, a very tiny portion of affluent AMT payers might be able to avoid the tax by electing to take smaller deductions where it’s allowed. If you take the smaller standard deduction instead of itemizing or if you deduct state sales taxes instead of higher state income taxes, you may simultaneously raise your ordinary tax bill and lower your AMT enough to tip the balance in favor of regular taxes. This complicated strategy, though, is best done by an accountant.

Chances are there’s nothing you can do for 2007, but consider making an appointment with a pro to see if you can skirt the AMT at least every other year.

How to avoid an audit 

Find a four-leaf clover and steer clear of black cats: To some extent, being hit with an audit is just bad luck. Even if you don’t do anything to raise an IRS computer’s eyebrows, you could end up being plucked at random. Nobody outside the IRS knows for sure how the nonrandom returns are identified – and the agency isn’t telling. But most tax experts agree that having outsize deductions is one red flag.

Martin Kaplan, author of “What the IRS Doesn’t Want You to Know” and a C.P.A. with 35 years of experience handling audits, says that writing off more than 25% of your income would likely get your return marked for review. And while the IRS used to look hard at the home-office deduction, the emphasis these days seems to be on people reporting small business losses on Schedule C, says Frederick Daily, author of Stand Up to the IRS.

That said, as long as you have backup, you should claim what you are due, even if doing so might raise the likelihood of your being audited. While tax evasion is bad, tax avoidance is perfectly legal. An audit certainly won’t be pleasant, but it should be bearable and affordable if you have the proper paperwork to make your case.

Don’t want to hear from the IRS at all? Go back and check your numbers. Even TurboTax and Tax Cut can’t stop you from keying in the wrong digits. These simple mistakes won’t lead to an audit, but they could trigger an “assessment notice” – in other words, a bill.

What if you can’t file on time?

Good news: You can have a six-month extension. Bad news: You still have to pay your taxes by April 15. File Form 4868 (download a copy from irs.gov or your tax prep program will provide one), and use last year’s return to estimate what you owe or let your tax software do it for you. It’s better to overestimate and get a refund later; if you’re under by more than 10%, you’ll owe interest of 7% on the amount you underpaid by, plus a penalty of up to 25% of the underpayment.  

Can’t pay what you owe?

First make sure you’ve done everything you can to lower your tax bill. If that doesn’t help, you’ll have to pay up.

You can raise the dough any number of ways, including shaking down your first cousin or selling your least-favorite yacht. You can also qualify for an installment plan if you can prove to the IRS that you don’t have sufficient assets or income to pay now. You’ll be charged a $105 setup fee ($52 if you okay a direct transfer from your bank) and a variable interest rate on the balance (7% now).

Otherwise, use the lowest-rate loan you can. Tapping a home-equity line of credit may be the best deal. But you also have the option of paying by credit card through Officialpayments.com or Pay1040.com. Both hit you with a “convenience fee” equal to 2.49% of your tax bill, and then you’ll have to eat the interest charges. Wherever you get the money, pay off the debt as quickly as you can.

Be smarter about taxes next year.

Stop missing out on easy money Label a folder “2009 taxes,” and throughout the year file receipts for anything that might qualify as a deduction.

Bring home more cash If you got a refund this year, you lent money to the government interest-free. Better to owe a bit. Adjust your withholding so less of your paycheck goes to the IRS. (Go to irs.gov and search for “withholding calculator” to figure out the right number of exemptions.) Then arrange to have that bump in take-home pay go directly into a money-market fund. That way the interest earned is yours, not the IRS’.

Look up your tax bracket Knowing what you pay on every extra dollar you earn can make you a more tax-savvy investor. After you file, find the tax-rate tables at irs.gov (search for “tax rate” and pick the first result) and see what bracket your taxable income (line 43 of your 1040) puts you in. Armed with that, you can judge whether you’re better off investing in tax-free municipal bonds or taxable bonds. To do the math, divide the muni yield by 1 minus your bracket, expressed as a decimal (or 0.72 if you’re in the 28% bracket). The recent triple-A-rated five-year muni yield of 3.1%, for example, is the same as earning a taxable 4.3% if you’re in the 28% bracket. Compared with five-year Treasury yields of 2.9%, it’s a clear winner.