I once read in a book by famous dutch typographer that he believes in something that he calls the “unconscious eye” and of which seemingly typographers of a very old school (as of for today such layout work would appear as mere waste of paper) had always been aware of. Meaning that if the eye focuses on an object (let’s say a word to read) it always also keeps track of things that happen outside its focused view partition. So when in excellent books we find much space around text blocks (a good portion less on the inside of a double page because here its distances would amount) it is to give the eye undisturbed white space in these unconsciously perceived marginal areas. This helps a great deal in making the text better readable.
When I design letter glyphs and pass over to those minor corrections (which someone else may hardly recognize, at all, but are sometimes so decisive in adding to our fonts that liveliness which we so hardly gain for in modern almost “mathematic” design process) I help myself with the unconscious eye effect. When I elaborate certain tiny details (as here the inner ‘A’ counter form) I use to keep my metrics window open with some letters typed and then focus on just another letter than the one I opened in glyph window to work at. With the help of fast keyboard steps of one unit I modify Bézier curve tangent points. Very rapidly back and forth while observing the letter in question only in the “corner of the eye”. Until something tells me “stop”. Then I go on to other details that (always in metrics window) seem to need optimization… How do you work?