It's becoming more and more common for guys to let his girl choose her own engagement ring, but that's not always practical. More often than not, you'll want it to be a surprise, and not a little one. But choosing a ring isn't quite as simple as it sounds. You'll want to make sure she actually likes what she's going to be wearing every day, it needs to fit and be comfortable, and it needs to look good on her hand. Here's a quick guide on how to go about figuring what you need to do before getting down on one knee.

Take notice. Pay attention to the types of jewelry she wears. Does she like gold, silver, platinum, white gold? Most people have a very strong preference, so this is the most important step. If you're unsure, start paying attention or look through her jewelry box while she's out. Asking friends and family is never a bad idea (as long as you're sure you can trust them not to reveal your secret).

Diamond shape. If it comes to it, you can simply buy a diamond and let her choose the setting later on. The diamond is more important than the ring itself partly because it's the most expensive part, but also because its shape needs to match her hand. An elongated diamond might be good for short fingers, or a round diamond might be better for slender fingers. On rare occasions, some girls don't even like diamonds and would prefer a ruby or emerald.

The setting. If you do purchase a full ring with diamond and setting, it will be something special to her, so you need to make sure she actually might like it. Settings can always be altered, reshaped, or remade, so it's less important than the actual diamond. If you need to figure out what size she wears, take a piece of string and measure her finger while she's asleep. If she's a light sleeper, ask her family.

Considerations. What type of ring will be practical for her? Pointed style diamonds usually have prongs that can catch on clothing. Take her job into consideration. If you want something really special, you can always visit a real jewelry maker and custom design your own ring, too. You can even take a lost wax class at a local community college and actually make one yourself for the absolute, most special engagement ring you could give her.