Pretty Easy - Whatever the first name of the DH is, his middle name has to start with the next letter in the alphabet. And it flows through the whole set. If you reach the end of the alphabet before your set finishes, just go back to A.
Start the first name with any letter you want, just follow the alphabetical sequence.
Example
DH:
Victor WallisDW:
Xanthe Yasmine
DD:
Zara AramintaDS:
Basil CadeDD:
Dahlia Everest
DS/DD:
Frederic Greyson /
Helena IsabelDD:
Juniper KatrinaDD:
Lara Midnight
DS:
Nathaniel OwenDS:
Preston QuinnDD/DS:
Raya Sadie /
Tennyson Ulrich
Victor &
XantheZara,
Basil,
Dahlia,
Fred,
Helena,
June,
Lara,
Nate,
Preston,
Raya and Tenny.