Twenty-Ten, a default theme for wordpress, is really a simple and good theme. It mostly happens that you need to make changes in default Twentyten theme LIKE Change the width of the sidebar, change the menu text spacing etc. When that kind of changes are required, what most of developers do they make all changes in default Twentyten theme. That is not the correct way.
When changes are required, Don’t Use Twentyten Theme. The reason why i am preferring not to use Twentyten theme is “every time you update WordPress all the default theme files get overwritten erasing all your keenly crafted edits”.
Solution for this is:
1. Make a copy of the Twenty Ten theme :- Making a copy is so simple. Just make one another copy of Twentyten theme and rename this copied theme with the name you want to give. FTP path for themes folder is /wp-content/themes/ .
2. Update style.css :- open the style.css(/wp-content/themes/twentyten/style.css) file in a text editor. At the top of the file you will see the following header:
Theme Name: Twenty Ten
Theme URI: http://wordpress.org/
Description: The 2010 theme for WordPress is stylish, customizable, simple, and readable — make it yours with a custom menu, header image, and background. Twenty Ten supports six widgetized areas (two in the sidebar, four in the footer) and featured images (thumbnails for gallery posts and custom header images for posts and pages). It includes stylesheets for print and the admin Visual Editor, special styles for posts in the “Asides” and “Gallery” categories, and has an optional one-column page template that removes the sidebar.
Author: the WordPress team
License: GNU General Public License
License URI: license.txt
Tags: black, blue, white, two-columns, fixed-width, custom-header, custom-background, threaded-comments, sticky-post, translation-ready, microformats, rtl-language-support, editor-style, custom-menu
All you need to change is the theme name FROM:
Theme Name: Twenty Ten
Theme Name: <Name you want to give to your theme>
Done. Now when you log into your dashboard and click on “Appearance” you will see your new theme. Just click on activate to use it. Now you can tweak the theme to your hearts content and not have your work erased every time there is a WordPress update.