Lace.
On their wedding day, Lily wore a dress made of the finest antique lace, preserved carefully throughout the generations with the aid of Dr .R. K. Ick's antique preserving potion sold in select wizarding chains.
Andromeda Tonks had worn it at her wedding, having managed to take it with her when she ran away from her home, Nymphadora Tonks had worn it at her quiet, secret wedding, and now Lily Potter was wearing it at her much-publicized wedding.
Andromeda was beaming at them, and Teddy knew that she was already thinking of her future great-granddaughters wearing the lace dress at their own weddings.
Teddy was beaming too- he had never grinned so much in his life as he did on his wedding day.