WYSIWYG editor in WP 3.2 plugin

Look how I did it in my Meta Box Class:

$editor_settings =  array (
    'textarea_rows' => 8
,   'media_buttons' => FALSE
,   'teeny'         => TRUE
,   'tinymce'       => FALSE
    // a very minimal setup
,   'quicktags'     => array ( 'buttons' => 'strong,em,link' )
);
wp_editor( $content, $key, $editor_settings );

• $content is the already saved content you want to show in the editor.
• $key is the editor ID, it is used for the markup.
• For possible settings see wp-includes/class-wp-editor.php and the rather short Codex page.

Visual output:

You shouldn’t need a separate CSS file.