I think everyone gives clues about what they would like to have but wouldn’t ever request. You have to be vigilant to see them. Watch what ads she studies in magazines. Or what she admires when you shop together. Study the style of her clothing and select something similar. Look at the type of jewelry she wears and chose something with the same look. This is the best way to be sure she will like what you give her. If you want to take a chance, then buy something you like and hope she likes it too.