Updated for 7.0
Click on the Settings icon (the gear) located to the right of the search bar. This will take you here:
Under Stores, select Configurations. It will take you to this page:
Click on Accounting under the Configurations tool bar. A drop down will appear. Select Charge Types. It will take you to this page:
Select the yellow +Add button in the bottom right corner.
Click inside of the blank box to type in the new charge type.
Once you typed in your desired Name and Description, Select the green updated button in the bottom right corner.
These are sample names.