Unfortunetely it is currently EXTREMELY vague how we create ship sets/styles.
If you want to build ships with more than one style of part, Gauntlet had the great advice of checking the option of allowing all styles. This is also great for using otherwise hidden parts like Relic sections (some of the awesome campaign ships used these, work really well with most race styles).
EDIT: However the AI will use these ships sometimes, and you may end up with a cluttered list that really just feels like a ton of custom ships lying around.
Is very useful for setting up the XMLs and such, but personally I still feel short on what to do... Even the most in-depth guide is only useful if you have a full list of ships already made, a custom race with it's own XML series, personally experience with editing scripts, and a PERFECTLY laid out mod folder.
I'm hoping Stardock make the process easier, but I guess I'm just being impatient. Besides, if everyone could do this stuff I think it'd become a cheap novelty and even the likes of the Iconian style would die out...
I don't know, sorry I'm not much help, I'm mostly stuck too.