There are many free Thesis skins available for download but for the one who wants develop or build his/her own Thesis skin should know some of the theme building basics. The Blank Thesis Skin is almost a blank skin and is made for the sake of skin customization.

RYT Brothers.com

Thesis theme provides Thesis Skin manager which allows you to switch to another skin whenever you want. If you want to build your own Thesis Skin, follow the steps below:

1. Create a directory and put it in the “custom/skins” folder.
2. Create function.php for writing your custom functions on thesis hooks.
3. Create base.css for applying custom styling to your skin.
4. You may need some images, create a folder for skin images and thesis-all-options.dat file for importing all options that you have set.

Here is an example of my blank-Thesis-Skin folder,

Customizing base.css :

First of all we need to specify the name, version, author, etc like we do in the normal themes.
So following lines goes at the very first in base.css

/*
Skin Name: Blank Thesis Skin
Skin URI: http://www.rytbothers.com
Description: This is a free blank thesis skin for customisation.
Version: 1.0
Author: RYT Brothers
Author URI:        http://www.rytbrothers.com
*/

Customizing functions.php :

We are adding our own CSS file in the theme so we need to include it.
Here is how you can include base.css

add_action(‘wp_head’, ‘rt_main_css’);
function rt_main_css() { ?>
<link media=”screen, projection” type=”text/css” href=”<?php echo SKINURL; ?>main.css” rel=”stylesheet” />
<?php
}

And now that you are done with base.css and functions.php, you can now do your customizations. Look for the available list of hooks that thesis provides for customizations.
I have created a thesis blank skin for customization. Download Blank Thesis Skin and customize it in your own way.
Link:Download Blank Thesis Skin