Twitter don’t allow you to create multiple Twitter handles using same email address. If you want to create multiple Twitter accounts but don’t want to use different email addresses, here are some tricks you can use.
Hotmail / Outlook
Recently Microsoft releases aliases feature for email address. You can add alias for your email address other than primary one. So you will have multiple email addresses to point to single mail box.
So for multiple twitter handles you can create multiple email aliases and you can use it while signing up for Twitter.
Google / Gmail
Google does not consider dot (.) in your email addresses
e.g. following addresses are same
So you can create multiple email addressed using dot (.) in between your email. These multiple email addresses you can use to sign up Twitter handles.
Enjoy Twitter 🙂 — Other tricks are welcome.