help with organization

Hi -- I was looking for some helpful ideas and feedback on ways you keep yourself organized. I know many people may rely on iPad's or laptops or cellphones.... but are there other things you do to keep yourself on track, to manage your time, and to ensure nothing falls through the cracks?

I wonder how you organize your day, how you ensure you get back to people on issues, and how you keep up with the needs of those you manage.

Is there anything related to becoming more productive and organized that you wish you had learned sooner?

Thanks!