Scramble your real name. No one will know. Make it an anagram, meaning that they are words that can be rearranged to form, in this case, your real name. Look to social media. If you have a social media account, you can use the same username as your social media username (if it is not taken), but you may not want to do so if you are a famous user. Think creatively. Have any passions, including computers, languages, companies, etc. ? Choose a username suitable for your interests. Don’t choose a username that promotes another business, flags you as a vandal, impersonates an admin, or is just plain annoying. Those get blocked quickly.
