Memorize the natural notes on your low E (6th) and A (5th) strings:
Minimum: Given any natural note, be able to find it quickly on both the low E and A strings. Using the attached PDF, know how to find the same note one or two octaves higher on a different string. Know how to find sharps and flats between the natural notes.
Ambitious: Memorize the octave shapes. Be able to find any note on any string with no external reference.