Steps

1. Follow the link - http://twitter.com/apps and fill in the form as shown below. You can create account if you don’t have one here as well.

2. If everything is OK you will be redirected to the Create Application page. Press Create Application button and you will then see the form like shown below.

3. Application name, app description and callback url are required fields. Then type any anonymous url in website section and press Submit. You will then see this page.

4. You will now see the information you need to set your twitter account on the next page.

5. Copy Consumer key and Consumer secret and simply paste to Theme options -> Twitter panel