The best way to get your loved one the diamond ring she'll love and cherish for always is to let her choose her favorite diamond ring herself. But if you are worried she'll pick out a ring with the biggest diamond in store or you simply want to get down on your knees and surprise her with that big question, then the second best thing is to choose for her.

Buying a diamond engagement ring is pretty tricky since you are a man. Here are easy guidelines for you to follow before heading out to a jeweler's in town or visiting an online jewelry store. Just make sure you're well-prepared and know how to buy a diamond ring before you really buy one.

1. Do you know what kind of metal does she like to wear? - Every woman is different. While some prefer gold jewelry, others adore white gold and platinum. Have you noticed her jewelry? Is her necklace in gold or silver color? What about her earrings and bracelets? If they're all the same, and she kind of wears them all the time, then that's her favorite. So, when you buy her a diamond ring, you'll have to look at either the ones in gold or the ones in white gold or platinum. Note that white gold is cheaper than platinum. It will be a lot easier for you.