Logged In and Logged Out Shortcodes

Just encapsulate the content you want to show only to logged in users or or only to logged out users like this:

[loggedin]Visible for logged in users only[/loggedin]

[loggedout]Visible for guests only[/loggedout]

The Code for the two shortcodes

//logged in shortcode
function check_user ($params, $content = null){
  //check tha the user is logged in
  if ( is_user_logged_in() ){
    //user is logged in so show the content
    return $content;
  }
  else{
    //user is not logged in so hide the content
    return;
  }
}
add_shortcode('loggedin', 'check_user' );

//logged out shortcode
function check_user_out ($params, $content = null){
  //check tha the user is logged in
  if ( !is_user_logged_in() ){
    //user is logged in so show the content
    return $content;
  }
  else{
    //user is not logged in so hide the content
    return;
  }
}
add_shortcode('loggedout', 'check_user_out' );