Nothing stops investors from making contributions at the beginning of the year, a full 14 months before the final deadline, he says. "Contributing at the beginning of the year can make quite a bit of difference over the long term. It depends on your overall rate of return," says Armstrong.

The problem with that is many people don't have the funds available early in the year, says Jamie Golombek, vice-president of tax and estate planning at Aim Trimark Investments. "We recommend trying to make the contribution early ... but it may not be practical."

The benefit of early contributions varies depending on the amount of return your portfolio generates and the number of years you contribute at the beginning of the year as opposed to the end.

Golombek provides an example an "early riser" investor, who makes the maximum RRSP contribution at the beginning of the year, compared with the "late arriver" investor, who makes his contribution 14 months later.

Golombek looked at the impact over 20 years based on a 7-percent return, increasing the maximum contribution according to the proposed government increases to the limits (which are $16,500 for 2005, $18,000 for 2006 and then assumed a three percent increase each year after that).

By 2025, the "early riser" RRSP would be worth $938,188, while the "late arriver" RRSP would be worth $866,700. That's a difference of $71,488.

If you can't afford to pay the lump sum at the beginning of the year, Armstrong says it's still worth spreading the contribution over the year in a series of regular payments. By investing $596 every two weeks, it would be worth $110,000 more over 35 years than if you waited until the final deadline each year.

Be careful with over-contributions
Another way to squeeze more out of your RRSP contribution is to take advantage of rules that allow you to make a $2,000 over-contribution during your lifetime. While you won't get the tax break for the contribution, it can grow tax-free in your account.

Over 35 years at eight percent, Armstrong says that extra $2,000 could be worth an additional $27,000 to $29,500.

However, both experts warn the over-contribution rule is designed for mistakes and carries harsh penalties if you contribute too much. The government charges a 1-percent penalty per month for any amount that exceeds $2,000.

Earn RRSP room early
Another strategy is to start early. Contribution amounts are based on earned income shown on your tax return. So you can start collecting room even if it's from part-time earnings as a teenaged dishwasher.

"If a young person is working and they file income tax forms, it will create contribution room," says Armstrong.

The youth can then wait until she earns a regular salary to start contributing, which will lower her taxes, or she can start contributing right away and watch it grow.

Use a spousal RRSP
When it comes to maximizing contributions, Golombek says spousal RRSPs are one of the most overlooked areas.

A spousal RRSP allows a family to split income and try to balance the scale so that each partner has a comparable amount of money in their fund at retirement. The higher-wage-earner would claim the contribution for tax purposes, but the contribution actually goes into his spouse's account.

That strategy is also good if one spouse has a company pension and the other doesn't. To learn more about spousal RRSPs, check out our story on the advantages of using a spousal RRSP.

It can pay to borrow
If you don't have enough money to make an RRSP contribution, it sometimes makes sense to borrow the money. Depending on your rate of return and the length of time you keep the loan, "over the long term the return will far outweigh the interest costs," says Armstrong.

In a low-interest-rate environment, RRSP loans go for as little as 4.25 percent. Armstrong says the key is to pay the loan back quickly. Take the tax refund you receive for making the contribution and immediately put it against the loan to reduce the amount owed and then pay the balance off within a year, he urges.

Rather than borrowing to make an RRSP contribution, Armstrong suggests making regular monthly contributions and asking your employer to reduce the amount of tax taken off your cheque. You won't get a tax refund at the end of the year, but your RRSP will grow and you can avoid borrowing to make a contribution.

Look offshore
Lastly, Golombek advises maximizing foreign content in your RRSP. Canada accounts for only two percent of the world's capital markets and rules allow you to invest more than 30 percent of your fund off shore. You can use products such as clone mutual funds to get even more foreign exposure, he adds.

Check out Bankrate Canada's "How to reap the rewards of foreign investments" for more information.

Jim Middlemiss is a freelance writer and lawyer based in Toronto. He's a frequent contributor to the National Post, Investment Executive and Wall Street & Technology.