This is what i use.
In the header or layout tpl depending on your site put this,
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
And in the local.config.php make sure this is in there,
# Page encoding options
Config::Set('PAGE_ENCODING', 'UTF-8');
Config::Set('DB_CHARSET_NAME', 'utf8');