Wanted to do a spin-off thread to talk about this issue.
When creating a bio, I recommend choosing a species with some kind of culture you can play off of. In my case, there was nothing and I was forced to use another species culture.
I don't think it's always necessary to create a species that has been developed. There are lots of great ways to develop any species -- especially those that are canon, but have no background.
I'm interested to know, however, what other folks have found in trying to play an alien species. Because we're obviously not looking from their viewpoint, have you found it difficult to try and integrate yourself into the mindset of their culture? What if they don't have an onscreen culture? Klingons are pretty well developed and we know how they think -- but what about Katarians? Can we, and should we judge their entire race by the conniving of one person?
I'd love to hear how everyone has dealt with this