Form the habit of noticing carefully the intensity of the
illumination of the subject on the ground glass of the camera, so as
to judge correctly the time of exposure, as much of the successful
working of dry plates depends on the exposure; for although slightly
under-exposed or much over-exposed plates may by suitable
modification of the developer be saved and print good pictures, yet
they will lack the glow and balance that are characteristic of the
most perfect work.
Use a flat camel's-hair brush to remove any dust from the plate,
before putting it in the shield for exposure.
Always keep your developing solution in motion on the plate.
Fix your negative very thoroughly; leave it in the hypo 5 or 6
minutes longer than it is apparently necessary.
Never use hypo after it becomes discolored or turbid and deposits a
sediment.
Develop longer than you think necessary; a slow printing negative is
preferable to a weak one.
Keep your dark room and its contents very clean and free from dust,
and well ventilated.