EPS: Vector drawings. Embed the font or save the text as "graphics".
TIFF: Color or greyscale photographs (halftones): use a minimum of 300 dpi.
TIFF: Bitmapped line drawings: use a minimum of 1000 dpi.
TIFF: Combinations bitmapped line/half-tone (colour or greyscale): use a minimum of 500 dpi.