A couple of months ago, I switched from using Evernote to OmniFocus as a taskmanager. While I can’t function without a piece of software which is specifically built for managing tasks, e-mail is still the best way to quickly capture things to do. Before Captio, I would use Mail.app to send myself notes, but that were too much steps.
Then I found Captio (for iPhone). A simple app which does just one thing: it sends notes to one specified email address. A single tap and it’s gone and out of your head.
I’ve set up a ‘Mail Drop to Inbox’ address with OmniFocus, so with a single tap I’ve added a task to my taskmanagers’ inbox.
Make sure to take a look at your process for storing and processing tasks once in a while: there are probably things you could change to make your workflow more effective.