Sorry, but this isn't a how to. Or at least not for the modern era.
"From the Gilded Age until 1914, more than 100 American heiresses invaded Britannia and swapped dollars for titles--just like Cora Crawley, Countess of Grantham, the first of the Downton Abbey characters Julian Fellowes was inspired to create after reading To Marry An English Lord. Filled with vivid personalities, gossipy anecdotes, grand houses, and a wealth of period details--plus photographs, illustrations, quotes, and the finer points of Victorian and Edwardian etiquette--To Marry An English Lord is social history at its liveliest and most accessible."
This gets 4.4 stars on 45 reviews, with one 1 star and 2 two star dissenters. This is a bit of an oddity, as it's 365 pages are listed as being optimized for larger screens: something usually seen in over in the KKDD. Digital list price is $15.95