How to change Skins/Templates
You can change the Logo of the wiki by altering the $wgLogo variable in LocalSettings.php to the name of the image you want to use as a logo.
Please note that this logo should be placed in the /skins/common/images/ folder.
You can change the icon that is displayed in the address bar of your browser by changing a value in the /includes/Skin.php. Change the line from
'href' => '/favicon.ico' to 'href' => '/path/to/your/favicon.ico'.
You can create a skin all by yourself by following the steps provided below:
Go to your mediawiki directory;
Copy the monobook directory and name it with the name of your skin, exempli gratia: mywikiskin;
Copy the MonoBook.php file and name it with the name of your skin, exempli gratia: MyWikiSkin.php;
Edit MyWikiSkin.php and change the class name to SkinMyWikiSkin, exempli gratia: class SkinMyWikiSkin extends SkinTemplate;
In MyWikiSkin.php, change make the other class to have your skin name together with the word Template, exempli gratia: class MyWikiSkinTemplate extends QuickTemplate;
In MyWikiSkin.php, make $this->skinname to have a string value of your skin name, exempli gratia: 'mywikiskin';
In MyWikiSkin.php, make $this->stylename to have a string value of your skin name, exempli gratia: 'mywikiskin';
In MyWikiSkin.php, make $this->template to have a string value of your skin name properly capitalised with the word Template, exempli gratia: 'MyWikiSkinTemplate';
In your mywikiskin directory edit the image and CSS files;
Edit and customise MyWikiSkin.php as you please;
In LocalSettings.php set $wgDefaultSkin = 'mywikiskin'.