These are some suggestions on how you can plug Superpolator into your drawing and production process. It’s by no means the only way of doing things.
Draw some glyphs in a font editor. Save the document. Duplicate the document. Open the dupe, change the glyphs by moving stuff around. Do not add or remove points, just drag them around. Make a narrow, or a wide, or a bold or a light, or a random or whatever. Change. Save all these fonts in UFO format. Put them together in one folder. Fire up Superpolator.
Make a new document. Define some axes. Import the UFO masters. Pick the one that’s going to be on the Origin. Pick each of the other masters and give them values on the appropriate axes in the Location Editor. Go to the Designspace panel, click somewhere in the field. Type some text, interpolated glyphs show up. If there is a problem, check the Report tab for symptoms. If you make changes to a font in the font editor and export to UFO, Superpolator will notice the changes to the UFO and update automatically.
The Instance tab lets you define points in designspace that you want to generate into fonts. Add some more. Give them names, edit locations. Select one or all instances, generate UFOs. Reimport the generated UFOs in the font editor, fiddle, save, generate font binaries.
One powerful application of Superpolator is to generate extrapolated instances, import them in a font editor, tweak them until ready, export to UFO. Reimport in Superpolator, either in the same location, or in a new place, extend the designspace.