Most women are sentimental, so it is important to treat this as an event, rather than just a gift.
Presentation is key, so on top of the gift itself, it must be beautifully wrapped and last, but certainly not least, must include a heartfelt card. Keep the funny cards for another occasion. Ideal romantic gifts can be anything from chocolates to her favorite bottle of wine. Again the key is to tailor the gift to the individual. Books of poetry are fantastic gifts, but make sure it's a poet she likes. If the relationship is a bit more serious, jewelry is always a pleasant surprise and doesn't necessarily have to be too expensive. A simple pair of diamond stud earrings are always a classic. Probably most romantic of all would be a nice dinner with just the two of you where you can just relax and enjoy each other. Fun, sexy gifts such as lingerie are great, too, but make sure they are classy and not raunchy.
Take Her Away
If you want to truly blow her away, a romantic trip is perhaps top among everyone's list.
It doesn't have to be expensive. Simply plan early and whisk her away on a weekend retreat somewhere both of you have always talked about going. The element of surprise will be key here, so make sure not to leave receipts out or ask her if she prefers first class or coach. Even a quick drive to the country with a packed lunch or dinner will melt her heart. If you like camping, for example, find a cabin in the woods and book a weekend trip. For added emphasis, you could even do her packing for her; that way she won't have a worry in the world, but only loving eyes for you. Plan romantic activities, such as taking long walks, canoeing and gazing up at the stars. Make sure to bring a camera along to capture all these moments and, later on as an added bonus, have your favorite photo framed and give it to her---just because.