In general, I work out the elements of each race that tends to distinguish it
from the others as an overall unit (in which there can be some variation, I
don't believe in totally monolithic, all-the-same races), and play those
throughout; I also create the aspects of each individual character within
that as a subset. Whe I write, I just have that info in the background, and
let the characters take me with them.

jms