<a href="{exp:shortlist:add_list}" class="btn btn-primary"><i class="fa fa-list"></i> Create New List</a>
The add_list tag returns a link that will create a new list for the current user. Unless supplied as part of the tag, the list will be created with a default title and set to be the new default list. You can change that using the supplied tag parameters, also all these values are editable by the user after the list is created.
<a href="{exp:shortlist:add_list list_title='Custom List' make_default='no'}" class="btn btn-primary"><i class="fa fa-list"></i> Create Custom List</a>
Creates a non-default list with a custom name. If there is already a list of the same title, a number in parenthesis will be appended (e.g. New List (2), New List(3)). The list title can be updated later by the user.