Sherlock-
Sherlock can't always express himself to you through words and he curses himself for it. Because of this however, he often buys you little gifts to show you how much he loves you. This is normally a little something which represents your beauty and elegance like a necklace.

John-
John knows how much you absolutely adore Disney. You own loads of Disney merchandise and just love it when you are able to get an excuse to buy more. Sadly though, you are not rich enough to go to Disney land with John so he secretly decided to get you the next best thing... A sterling silver bracelet. Disney of course...

Mycroft-
After watching the movie 'Titanic' (and crying for several hours) Mycroft was set on treating you like royalty, just like how jack treated rose. So when he spotted a necklace which reminded him of the heart of the ocean, he just had to get it for you. You love it, and love him even more.

Greg-
Greg doesn't like huge flashy jewellery. He insists that it looks 'tacky' and 'try-hard', so when he does buy you jewellery, it is something beautifully simple. Just a pair of small diamond studs that really show how much you mean to him every day...