To prevent any hieroglyphics on your website, make sure everything is in the right format. Here is a full range example for Unicode (UTF-8).
First make sure that you safe every file (.php, .js, .css, etc.) correctly under the UTF-8 encoding. If you use UTF-8 with BOM you might get some disturbing space in the beginning of your web document.

For PHP:

header('content-type: text/html; charset=utf-8');

For HTML:

 <meta http-equiv="content-type" content="text/html; charset=UTF-8" />

...or short in HTML5:

<meta charset="utf-8" />

Not exactly necessary, but also possible is a tagwise setting, i.e. for submitted form data:

<form accept-charset="utf-8">...</form>

For MySQL:

SET NAMES 'utf8';
SET CHARACTER SET utf8;

Additionally:

SET character_set_results = 'utf8',
character_set_client = 'utf8',
character_set_connection = 'utf8',
character_set_database = 'utf8',
character_set_server = 'utf8';