When playing as the Empire, I prefer to name my ISD's using the international alpha code: Alpha, Baker, Charlie, Delta, Echo, .... Other Imperial ships classes (if worthy) get typical Imperial names, mythological creatures, or carnivore names. For the Alliance, I like to name the escort carriers and Liberator cruisers after WWII US aircraft carriers: Enterprise, Lexington, Yorktown, Wasp, Hornet, etc. Big cruisers and heavy ships get state names (similar to WWII US battleships). Other ships get animal names or ancient weapon names.