There are plenty of methods for managing your time and the one you use is a personal preference. For a couple of suggestions, you can check out the Eisenhower Matrix technique for managing tasks. This method also helps you effectively use your time by prioritizing your workload.
Additionally, you can try setting up a block schedule to focus on one task at a time. You plan each day or week in advance by scheduling time for each item on your list. Check out our how-to on setting up a block schedule in Outlook Calendar for further details.