Composing a mail in a smart-way will save you some time as well some internet bandwidth. Generally people launch the mail site/program, wait till inbox loaded and then hit the Compose button to load Compose window. Composing mail this way takes extra time and extra internet bandwidth to load all inbox messages first even you don't wish so.
+Ilya Grigorik, Software Engineer from Google, shared a smart way to quickly compose a mail and skip aforementioned time consuming steps. This trick works across all browsers and desktop clients.
In your browser, enter mailto: command in the address bar. This will instantly load a compose window of your default mail client and will skip loading your inbox.
Suffix mailto: command with the recipient's mail id, if you wish to directly populate the mail address(es) upon loading the compose window. Add comma separated mail ids incase of multiple recipients.
Optionally you can pass values for the other fields like CC, BCC, Subject with the mailto: command. Passing such values will auto populate those message fields upon loading the compose window in the mail client.
Hope you will find this useful. Share your feedback and experiences in the comments.