If your cookies are too tough . . .
You may have used too much flour or a flour with too high of a protein content. Unless you want a chewy cookie, do not use bread flour. Check your measurements–the cookies may not have enough fat or the amount of sugar may be wrong.
If your cookies are too crumbly . . .
They may have too much sugar, shortening, or leavening or may not be thoroughly mixed. Try adding more eggs.
If your cookies are too hard . . .
