I email myself task multiple times a day. Instead of creating a new email every time, I saved one of the RTM emails (just press Save while the email is highlighted or opened) that I sent before and keep reusing it over and over again. I just change the task (subject), list names, times, etc. It's better than a draft email because the draft disappears after you send it first time, while a saved email sticks around forever.

To speed up the whole process. I press letter 'V' on the BB keyboard (default shortcut key for Saved Email) and that opens the saved email folder. Open the email of your choice (you can have different ones with different list names saved) and click on Edit option. Then make your changes and send. Your RTM address will be already filled in.

See more on email format here: http://www.rememberthemilk.com/help/answers/sending/emailinbox.rtm