Save As Preset ...
from
the Presets
menu. You will be prompted to give your
new Preset a title:
Enter some text that describes your new Preset; this text will
appear as a new Preset in the in the Presets
menu. When selected, this Preset will
set the Image Fitting tool to the same state it was in when you saved the Preset.
To remove a preset from the menu, click on Manage Presets ...
, and
delete the Preset you want to remove.