So the scenario is:

• I have a domain say idealwebtools.com and I am planing to shift it to a new domain SEOforClients.com
• Now I am ranking for some good keywords from where I get good traffic like Chirkut, Paypal hack, meta title length etc
• If I shift to new domain, will I lose all my traffic and ranking?

Answer to Shifting the domain, losing the ranking

Yes, you will if you don’t let the search engines know in a proper way as they are scammers who buy old domain to promote their new domains. Let me explain how to retain the best of both world, the new cool domain name and the old ranking & traffic (I did it for idealwebtools.com, so I can share some good examples):

Search Engines know that shifting of domain can happen

Google and other search engine knows about it and they have a provision for it. Google’s site says:

If you’re planning on moving your site to a new domain, here are some tips that will help you retain your site’s ranking in Google’s search results. Your aim is to avoid 404 (File Not Found) errors when users click on links to your site.

• If you’re changing your domain because of a rebrand or redesign of your site, you might want to think about doing this in two phases: first, move your site; and secondly, launch your redesign. This manages the amount of change your users see at any stage in the process, and can make the process seem smoother. Limiting the number of changes at any one time can also make it easier to troubleshoot unexpected behavior.
• Use a 301 Redirect to permanently redirect all pages on your old site to your new site. This tells search engines and users that your site has permanently moved. We recommend that you move and redirect a section or directory first, and then test to make sure that your redirects are working correctly before moving all your content.Don’t do a single redirect directing all traffic from your old site to your new home page. This will avoid 404 errors, but it’s not a good user experience. It’s more work, but a page-to-page redirect will help preserve your site’s ranking in Google while providing a consistent and transparent experience for your users. If there won’t be a 1:1 match between pages on your old site and your new site (recommended), try to make sure that every page on your old site is at least redirected to a new page with similar content.
• Check both external and internal links to pages on your site. Ideally, you should contact the webmaster of each site that links to yours and ask them to update the links to point to the page on your new domain. However, if this isn’t practical, make sure that all pages with incoming links are redirected to your new site. You should also check internal links within your old site, and update them to point to your new domain. Once your content is in place on your new server, use a link checker like Xenu to make sure you don’t have broken legacy links on your site. This is especially important if your original content included absolute links (like www.example.com/cooking/recipes/chocolatecake.html) instead of relative links (like ../recipes/chocolatecake.html).
• To prevent confusion, it’s best to retain control of your old site domain for at least 180 days.
• Use the Change of Address tool in Webmaster Tools to notify Google of your site’s move. (Note: To use the Change of Address tool, you must be a verified owner of both the new and the old sites.)
• Add your new site to your Webmaster Tools account, and verify your ownership of it.
• We recommend that you create and submit a Sitemap listing the URLs on your new site. Submitting a Sitemap is a way to tell Google about pages on your new site that we might not otherwise discover.

Once you’ve completed all these steps, you can use your Webmaster Tools data to check that everything is working correctly. While it can be some time before Google crawls your old and new sites, and all these changes take effect, here are a few ways to check that the process is working correctly:

• Check the web crawl errors for both your old and new sites, to make sure that the 301 redirects from the old site are working properly, and that the new site isn’t showing unwanted 404 errors.
• If you’ve submitted a Sitemap for your new site, the Sitemap Details page lets you see how many URLs in your Sitemap we’ve crawled and indexed.

Read the latest at http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=83105

Steps for shifting a domain without loosing the ranking

1. Make the new site live and check if everything is ok with a robots.txt block or .htaccess folder protect (Folder protect is best). Make sure the old website content is kept as it is for atleast few weeks (if possible).
2. Now see if you are retaining all the old URLs, in case if you are retaining all the URLs as it is then you can do a page by page redirection like
   
RewriteCond %{REQUEST_URI} ^blog$
RewriteRule (.*) http://www\.seoforclients\.com/hr/ [R=301,L]

   Here I am redirecting all the blog pages to the new URL at SEOforClients.com, see few live examples:
   • http://www.idealwebtools.com/blog/folder-protect/ is redirecting to http://www.seoforclients.com/hr/folder-protect/ &
   • http://www.idealwebtools.com/blog/orkut/ to http://www.seoforclients.com/hr/orkut/

   This is a pure one on one redirection when the URLs are kept the same.

3. Now what if the url is also changed randomly, say http://www.idealwebtools.com/blog/folder-protect/ is changed to http://www.seoforclients.com/hr-folder-protect-132/ (no specific patterns) and http://www.idealwebtools.com/blog/orkut/ to http://www.seoforclients.com/orkut-vs-chirkut/ (the patterns in not in your control). It this case you can use .htaccess to do a one on one redirection but for each you will need one entry like
   

   RewriteRule /blog/folder-protect/ http://www.seoforclients.com/orkut-vs-chirkut/ [R=301,L]

   Sometimes it can be too much work for a non technical team, you can shift the old domain to a wordpress and use a 301 redirection plugin like we are doing for http://www.seoforclients.com/links (which is redirecting to Google CSE). Do one on redirection as much as possible as it will then retain the link value.

4. Make sure that the new site doesn’t have links to old site, change the links from all the content.
5. Mention the change in Google, Yahoo and Bing webmaters as mentioned above.
6. Keep watching both the webmasters for old and new domain and see if there are any issues with it.
7. The ranking may take a little time to come back, so have a little patience.

In our case we have regained all the ranking that we had at idealwebtools.com.