I have made and posted over 20 races. I have tried to give my races as much back story as I can. Often I do races in groups, i.e., four "elemental" races, both a demon and an angel race, a race with 2 other races that have splintered off.
I have often though that it would be great if there was a method for them to always react yo each other in the same way as the make contact with each other in the game. Such as tagging them, maybe a conflict and a diplomatic tag that could be added in the creating of the race. It could be as simple as a number you input that if 2 races meet and have the same tag number they will always react the same. Example, I pick a conflict number of lets say 15322, and put it in on both my angel race and demon race, so that when they meet they immediately go to war and stay at war with each other. or two races that you want to always work together, you put a matching number in their diplomatic tag and they will always have they best possible relations with each other.
I know its an off the wall idea, but it could add a little more depth I think to the personality of the game and its races.
Thanks