If a variable is used frequently throughout your templates, applying the default modifier every time it is mentioned can get a bit ugly. You can remedy this by assigning the variable its default value with the {assign} function.

{* do this somewhere at the top of your template *}
{assign var='title' value=$title|default:'no title'}

{* if $title was empty, it now contains the value "no title" when you use it *}
{$title}

    

See also default modifier and blank variable handling.