I also tried to create a few races... somebody here suggested to use a basic stereotype for the race first (Like noble elves, greedy goblins) and to work from that. The problem is that this quickly becomes a cliche and makes it impossible for the race to have any depth.
I'd recommend to approach it differently. First, start with the races biology. Let's take a classical race: The Dwarves. They are small and heavy. The average dwarf is stronger then the average human. They have a similar metabolism to humans though they reproduce slower and live longer. Actually, they're VERY similar to humans.
Because they reproduce slower, it means that they will be much more defensive. They will also watch out for the single child more and put more... efford into it. They'll isolate themselves, be less trusting. Their size would make it easier for them to live in plains because small size, combined with more weight doesn't just make swimming harder but climbing as well. I personally think that they would survive best in plains and hill-lands, would dig themselves tunnels and live more underground. They would be more peaceful - they can't just waste children in a war like humans. Also, they'll be more educated.
So, I imagine MY dwarves to be more peaceful... they live in plains and hilllands. They will build more machinery like mills and dams but also be common woodcutters and farmers. They'll also be more artistic, blacksmithes, painters... a small, peaceful community. They will have an army but try not to get involved in wars. But if they should get attacked, they will stay loyal and sacrifice much to protect themselves. They'll also trust outsiders less.