The easiest way to choose what to show on your screen is to select from your categories. They allow you to set a 'theme' to a TrilbyTV Player, and have it auto-refresh with new content, as it is added to the category. You could even create a category for a specific screen, such as "Reception Screen" and use that to manage what plays on it.
When editing a Players Default playback, or a schedule, click the Categories tab. Initially, All will be selected, which will playback any videos approved and marked to Show on TrilbyTV Player. Click the categories you wish to playback from. They will be checked to indicate they have been selected. Turn on Shuffle to enable random playback mode, otherwise, videos are played from newest to oldest. You can also Limit the player to only show the latest x items. This means the content is always the new stuff added.
Note: When selecting Category-based playback, TrilbyTV selects videos based on any of your chosen categories. For example, selecting Events and Front Screen would play back any videos tagged with the Events category OR the Front Screen label, rather than videos tagged with both Events AND Front Screen.