Buying a diamond can be an exhilarating but daunting adventure, especially if you're a newbie.

If I could offer only one piece of advice it would be this: Learn as much as you can about the 4Cs before you go shopping.

For the uninitiated, that's cut, color, clarity and carat weight. And I like to add one more - common sense.

Choosing the perfect diamond (and there's no such thing as the "perfect" diamond, although a few have come close) is as much a matter of personal taste as it is a matter of the diamond's characteristics.

Some couples are willing to forego quality for size, others prefer the brilliance of a flawless blue-white diamond over a larger stone with less clarity. You be the judge - but not until you're clear about those characteristics I mentioned.

Talk to any jeweler and they'll all give you a different opinion as to what they believe is the most important quality of a diamond.

According to Mayer Herz, Vice President of Diamond Acquisition at Mondera.com, "Cut is the most important consideration if you're on a budget. You can make up for low color and clarity if the stone is well cut."

However, Joseph Schlussel, Publisher of Diamond Registry Bulletin, says "I personally believe that color is the most important thing. Most people who go into a store today, they are told about cut. But I look at what you can see with a naked eye. I would put cut the last, because most people can't see it."

The safest all-round bet is to look for the overall "package", with the levels of cut, clarity, color and size as good as you can get for the price you're willing to pay.

Here are my tips to help you get the best value possible: