The available positions for your modules are defined in the templates/your_template/index.php file inside your Joomla directory. You can create a custom position by adding it into this file. For example, if you want to create a position named "custom", you should add the following code into the index.php file where you want the module to be displayed:

<?php if ($this->countModules('custom')) : ?>
<div>
<jdoc:include type="modules" name="custom" style="xhtml" />
</div>
<?php endif; ?>

now open the template.xml and add the position as <position> moduleposition name </position>

enjoy :)

1 - http://webkul.com/psd-to-joomla-services
2 - http://webkul.com/html-to-joomla-services
3 - http://webkul.com/joomla-tutorial/how-site-optimization-helps-in-seo-search-engine-optimization
4 - http://webkul.com/joomla-tutorial/joomla-web-services-and-extension-module-component-plugins-development-concept
5 - http://webkul.com/joomla-tutorial/easy-tips-to-improve-your-google-rank-with-joomla
6 - http://webkul.com/joomla-tutorial/how-to-add-xmap-sitemap-in-google-webmaster-tool
7-  http://webkul.com/kunena/search-engine-optimization-seo/joomla-seo
8 -http://webkul.com/joomla-seo-services