There are as many ways to build game worlds as their are people in gaming, but here is one. Fate in general isn't as worried about the little things in the game world if it isn't really all that exciting as other games are. At the basics there really isn't any need for world building in Fate, unless you just want to. Personally I love to. I have built a ridiculous number of multiverses over my decade of gaming, just because I like to do it. Anything can be treated as a character, but that doesn't mean you have to. An interesting way to start is to define areas of the game world and then just give an aspect.
First let's define our genre. I will go with Sword & Sorcery. For races lets give the "classics" (from D&D) and add in feline race, werewolf race, then two similar races to each other, one that is descendant of demon and another descendant of angels. So our races are human, elf, dwarf, halfling, gnome, orc, felina, cano, daemon and angal. I left the half races out for now. In fate you don't need to give any type of stats or anything. Having the races in your aspects could give reason enough to automatically give the mechanics of what they give. Me I like to have the options, I just don't like huge lists to look through, like in D&D, Pathfinder, GURPS and other games. I am finding that I like to give suggestions, but also encourage the freedom to build more for your specific game. In the Fate Toolkit in the stunt section, there is a great section that I think goes great with building mechanics of races called "Broad Stunts". This would be the easiest thing to do.
Combining the Broad Stunts and Combined Stunts sections you can make easy race stats. Either of these stunt types in my games will only be available via some kind of permission and prerequisite, to keep it special. Also it can be reversed to symbolize a race's negative things, like an orc's intelligence. I must warn you though, and this applies to all games and not just Fate, the Zero Sum. The Zero Sum is a problem that happens when there is too many bonuses and it ends up just being an equal roll anyway, so all the adding up bonuses is for nothing. So don't go over board on the race building.
I will split up the blog posts in to different parts. I would appreciate it if you like and share please.