Do they commonly have bright green skin or hazel eyes? Are there reasons behind these physical traits? Be creative. This is your race and your creation, so you have complete control - maybe add on a tail or extra arms if that is what you want. There are no limits to what you could create! Choose a theme: Is your race an elegant, peaceful race, or are they brutal monsters? This doesn't have to be religious beliefs. Do they have free or strict gender roles? Do they believe their rulers are the descendant of some divine being? The things they believe in will greatly shape the mentality of the race. There's no such thing as an entire race being all evil or all good. You can however make it so that another species believes they are all evil because of certain events in the past which created this stereotype. Are they exceptional fighters? Can they use certain types of magic?  Are they always bad tempered, etc.? How can they be killed? This is essential to identify, especially if your race will be at war with another race at any point in your story. Does your race have any close relatives? Was there interbreeding that caused a mixture of races? Is one race descended from another? How did they come to be as they are? Were there any defining aspects of their history that have shaped the way they are now? Build a culture for your race. How did they make their weapons? What do their homes look like? What did they do for entertainment?

Summary:
Write down the common physical traits of your race. Describe the beliefs of your race. Identify the race's strong and weak attributes. Identify other races. Explain the history of the race.