Define templates using keys:
Template.register("event-detail",
'<div class="event-detail">' +
' <h2>{{ title }}</h2>' +
' <p>{{ description }}</p>' +
'</div>';
);
Call templates in code:
var context = {title: "This is a title", description: "This is a description"};
$('#event').html(Template.render("event-detail", context));