Understand what you were hired to do and the results you are supposed to deliver.

If you don't know what your goals are, most likely you won't be able to identify and prioritize the specific tasks you need to work on to achieve those goals. 

Once you have your goals broken down into tasks, you have to work on those tasks one at a time. 

• Plan your frog for the next day at the end of the previous workday and block off time to work on that frog so you can tackle it with no interruptions.
• Make sure you have all of the things you need to do your work and a comfortable workspace to do it in.

After you start working on a frog, continue working on it until you can take it off of your to-do list.

• A tasks: things you must do - they're your frogs. 
• B tasks: things you should do. Replying to emails or attending meetings are often should-do tasks. 
• C tasks: nice-to-dos. You probably want to do them, but there are no consequences if you don't.
• ...

Identify the things that are holding you back, internal and external and eliminate them.

... to make better short-term decisions.

1. Define your goals and write them down.
2. Break those goals down into tasks.
3. Break those tasks down into the smallest possible subtasks.
4. Prioritize your tasks, and delete/delegate tasks you don't need to do.
5. Schedule time on your calendar every single day, ideall...

Schedule time on your calendar at the end of every workday for working on your frog the next morning, or create a recurring meeting for the first hours of every day to make sure you always have time blocked for goal tasks.