If Prince William gives Catherine another ring, I hope that it is a square one because that shape would suit her hand better. To continue, I think Catherine would look good in the Queen's fringe tiara (I believe it was Queen Mary's) and in that "triple strand" diamond necklace that was called the George VI in a book I read. Finally, when Catherine has her hair up for a tiara, I hope that she does not wear either shoulder pads or a wide neckline.
With Catherine's engagement day jewellery, I hope that William gave her the necklace and earrings (they look like sapphires) because I hate mean Rich People.