Display posts in 2-6 columns. Example:
[display-posts columns="2"]
This plugin adds a CSS file for the column classes. You can disable the CSS file if your theme already has column classes, or you created your own column classes and added them to your themes stylesheet.
Add this to your theme's functions.php file:
add_filter( 'dps_columns_extension_include_css', '__return_false' );
Download the plugin here, then upload it to your website. Plugins > Add New, then click "Upload Plugin" at the top of the page.