I wanted to share best practices using Git with Xcode project with everyone who had trouble with Xcode and Git.
If you have made any changes to your code and want to push just follow this steps:
Commit from gity (free excellent GUI git tool)
Pull from Xcode 4.3.2 (File->Source Control->Pull) (Xcode is good at solved .xcodeproj file conflicts).
Solve conflicts using Xcode (if any)
Commit and pushed from gity (or command line which is much more convenient).
If you want to get latest updates just pull from Xcode.