afterglow will work mostly by itself, but you can change how it behaves by using player parameters.
There are four mandatory parameters which you must pass to the video element, and there are some other parameters you might want to know.
All parameters you want to use must be applied to the video element. Like this.
<video class="parameters" id="go-here" width="XY" height="XY" some-other-parameter="some-value"> <!-- sources here --> </video>
Exception from the rule: resolution switching
There is one parameter, that is actually applied to the sources and not to the player itself. You can read more about resolution switching in the video sources guide.
Updated less than a minute ago