1. Watch this video of David Allen ("Getting Things Done").
2. Do a "core dump" of all the things you need to do into an electronic todo list manager, such as OmniFocus.
3. When you get to your office open up your todo list manager AND do not check email. Figure out your agenda, adjust, and (ideally) work for an hour on your stuff. Then check email.
4. Figure out the specifics that work for you, and find the programs, apps, and system that gets you quickly and efficiently into you work mode. While I use OmniFocus, I know it's not for everyone. It works for me, and I've made it work for me. You may prefer EverNote or some other system.
Why? Time. Time is the most precious resource we have, and if you are more efficient, you have more time to allocate to your teaching and research that is meaningful. It helps you get better. If you're always in catch-up mode, then your tasks are controlling you, and you have no margin for error. If you get sick or miss an appointment, you're way behind.