Manage the Desktop
Basic Desktop settings can be found in System Preferences, Desktop & Screensaver panel. Here you can choose the background and how often it changes. See: Desktop & Screen Saver
Some items will appear on the desktop by default, these include any connected USB drives, or disk images.
Stacks are an amazing feature for tidying a messy desktop in no time at all, two clicks for the changes below.
How useful that is depends on the user. At the end of the day organising files and deleting old files manually is better than just making them look neat with an automated system.
Desktop without Stacks
Stacked by Type
Each type of file gets its own stack
Stacked by Date
Files are stacked by date
To use stacks, alternate click in a space on the desktop and select the option to Use Stacks. Once Stacks are active Alternate click will allow you to turn them off or under that is the option for deciding how stacks will Group items.
Apple guide How to Use Stacks on your Mac
If you are not using Stacks, then right click in space and you will see options to Clean Up and Clean Up By. Both of these options simply tidy the Desktop icons by sorting them and placing them in a neat grid.
Final option when you Alternate Click on the desktop opens a simple tab where you can set a variety of features, all self explanatory. Including the size of text, icons and grid.
