NEW YORK (CNN/Money) - When it comes to taxes, "Que sera, sera" should not be your theme song.

True, there's very little you can do now to change your 2002 tax situation (with the exception of investing in certain tax-sheltered accounts). But there are plenty of relatively painless things you should consider doing if you want to save on taxes down the road.

"If you plan ahead and are conscious of taxes throughout the year, you'll save a lot of stress and possibly money come next April," said Jackie Perlman, senior tax research analyst for H & R Block.

A couple in the 27 percent tax bracket could save more than $3,300 in federal taxes with four simple changes to how they save, borrow and give away their money. That $3,300 figure, mind you, doesn't even include what they could save in state taxes, which could add up to another $500 to $1,000 depending on their state.

The sad fact is, most Americans come nowhere near to the limit for 401(k) contributions. According to Hewitt Associates, only 75 percent of employees are taking advantage of this tax-sheltered savings plan, and the average contribution is a paltry 6.5 percent of pre-tax income.

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A couple earning $100,000 combined could sock away as much as 24 percent of their income before they hit the ceiling for contributions, which is $12,000, per person, in 2003 and scheduled to increase by $1,000 a year until it reaches $15,000 in 2006.

By increasing their contribution from 6.5 percent to just 10 percent of their pretax income, in fact, this couple would be able to put an extra $3,500 in their retirement fund each year, and save more than $1,000 in federal taxes. But their total take-home pay would only shrink by less than $100 per biweekly pay period.

"If you're weary of the stock market you can still save in a 401(k)," said Perlman. "Just choose a more conservative option. Some plans will even let you allocate to a money market fund."

One perk that is increasingly offered by employers is a flexible spending account (FSA). Employees are able to contribute money to FSAs -- pretax -- via paycheck deductions. That money can then be used for qualified medical and childcare expenses.

For a medical FSA, employers set contribution limits, typically in the $3,000 to $5,000 range. For a dependent-care FSA, the contribution limit is $5,000.

A couple in the 27 percent tax bracket would save $270 in federal taxes a year just by putting away $1,000 for medical expenses. By then setting aside the full $5,000 in a dependant-care account, they would save another $1,350 in federal taxes.

Despite the tax benefits, many people shy away from these savings accounts because they are afraid that if they don't use the money they'll lose it, which is true. But if you come up with an estimate of predictable expenses and make a point of tracking your out-of-pocket costs, you should have no problem using all of the money in your account. (Click here to read about ways to use your FSA savings.)

"My recommendation is to start small," said Perlman. "You'll be surprised by just how many things you can use your FSA money for."

Most employers won't let you change your FSA options in the middle of the year, unless you marry, have children or otherwise change your "status." So mark your calendar and make a point of saving via your FSA as soon as you have the opportunity.

Homeowners think of tapping their home equity when they need money for a renovation project or want to consolidate high-interest debt. The tax advantages of borrowing via a home equity loan or line of credit are just icing on the cake.

According to Mark Luscombe, principal analyst for federal and state taxes for CCH Incorporated, consumers should seriously consider borrowing via home equity any time they need a loan. In most cases, you can deduct the interest paid on a loan of up to $100,000, regardless of how you use the money. The one caveat is if you are subject to the alternative minimum tax, in which case you can only deduct loans related to your home.

Of course, you'll still want to shop for the best rate possible and weigh that against any tax deduction. But assuming the interest rate is competitive, you could deduct $900 a year for a $15,000 loan with a 6 percent rate, paid off over five years. That translates into $240 in federal tax savings for our hypothetical taxpayers.

You don't need to be a Rockefeller to help your fellow man -- or take charitable tax deductions for your generosity. The average household made more than $1,600 in charitable contributions in 2000, according to Independent Sector, which represents more than a million non-profit organizations. For someone in the 27-percent tax bracket, that's worth $432 in federal tax savings.

As long as you itemize your deductions -- and most people with a mortgage do -- you can deduct up to 50 percent of your modified adjusted gross income for charitable donations.

Although the IRS only requires a written acknowledgement for donations over $250, you should make a point of getting a receipt for donations of all sizes. At the very least, keep a detailed log of all your gifts. You'll be surprised by how quickly they add up.

"People are generally pretty good at keeping track of things they write a check for but they're a little sloppier with the $5 they put in the collection basket at church or give to the organization on the street," said Luscombe. "A lot of people also fail to keep track of non-cash donations. They drop things off at Goodwill without making an inventory of what they gave."