Keep it simple. My inbox only contains mails that require an action at some time. If I have done this action, I immediately archive the mail. I often mail todo'

Keep it simple. My inbox only contains mails that require an action at some time. If I have done this action, I immediately archive the mail. I often mail todo's to myself so I have only one place for todo's. If I have to do something on a specific time, I put it in my online agenda. I have a separate setup for work and private, that's it. This works great.