Here is an example of a few JW Player variables that are easy to implement with a single line of code each.
*This example uses the JW Player version 6.7
This example demonstrates autostart, mute, repeat, and stretching. These can be set to 'true', or to disable them, simply remove the relevant lines of code from the player. The stretching can be set to "exactfit", "uniform", or "fill", depending on your needs. It is also possible to hide the controlbar using 'controlBar: "none",'. Clicking on the player will stop and start the video, but you won't have the option to change the volume levels or skip ahead on the time slider.
'Primary' tells the player which rendering mode to try first; in this case, flash. If not included, the player defaults to HTML5, which is compatible with most browsers and iOS devices and generally recommended. However, this is useful if you run flash-only advertising on your videos. The 'abouttext' variable is what will show when you right click on the player itself, and clicking this text will take you to the link specified in the 'aboutlink' variable.
For more help embedding the JW Player, check out their official help page here.