Different Final Cut Pro Rendering Options
The basic method for rendering is to select the render from the Sequence heading in the upper task bar. You can choose to either render a specific selection, which you choose in the Timeline, or you can choose to Render All. Within both you have a few different options for video rendering, as well as two for audio rendering.
In the video render options you are going to want to make sure that the first four options are selected at all times, which are Needs Render, Rendered Proxy, Proxy, and Preview. To get a full render of the footage you will select Full, and for the final selection you will have Unlimited. The difference between these is how much you want to be rendered in your file. For speed, you will usually just keep it set to Preview so that you can just render it enough to get playback in your Final Cut Pro project. Full is what you will need to actually see how the video looks completely, and this is a good option when doing online editing.
Audio works the same way as with the video render options, except here the hierarchy is relegated to only two options. You will need For Playback selected so that you can render the audio to play, but only Item Level will actually play it back at the right levels so that you can really tell what it will sound like.