Rainth the Orion is working ona an all Orion Female Crew
Gsith the Gorn is working to all Gorn and Orion Females
Qhi the Klingon is vaguely leaning towards all Klingon
Whiskers Human is trying to get 96% females on his ship.
T'Pel the Vulcan is going all female Vulcan
Karn the Klingon is not being picky at all.
Zeken is going for attractive women.
I find it is something you need to start Early it will take a lot of work to get Whiskers switched over and Qhi both of which are 50.
My main, Kuoron, is sporting a Lethean-heavy crew, both for Boff and Doff positions. Doffs also include some particular favourites, naturally, such as a handful of Gorn, Federation turncoats, a Vorta and a pair of Breen. But they're mostly Lethean.
What I'd REALLY like to see for my themed ship is to have those Doffs represented throughout the ship, rather than the insta-beamed-in mix of regular no-name KDF generics. Mmmm, yes!
I've done: Andorian, Tellarite, Gorn, Orion, Nausicaan Boff+Doff crews, and am starting on a Dosi crew, which will obviously be a lot harder. I started on a Cardassian one as well at one point, but largely abandoned it.
I wouldn't trust the Dosi...their eyes are too close together...