Attach the VR mount to your headset. It should be aligned as closely as possible with your eyes.
Use the free cable extender bundled with the mount to connect the controller directly to the computer.
Download the Orion SDK and run the installer.
Right-click on the new Leap Motion system tray icon and click Settings. Go to the Troubleshooting tab and select "Recalibrate Device. We recommend a calibration of 90%. (If you experience issues with calibration, watch this video.)
On the General tab, check Allow Images. This allows apps to access the infrared video passthrough.
Depending on which headset you're using, you may need to develop your own integration for the Leap Motion Controller and your preferred game engine. This blog post covers the fundamentals you need to get started.