An Overview of the Zone System
This chapter briefly summarizes the Zone System method of exposure and development and answers a number of questions students usually ask at this point in the process.
What you have learned is that when the subject being photographed is flat or contrasty, you need to control the contrast of your negatives.
Here are the general steps for producing consistently printable negatives:
Previsualize your subject in terms of the finished print. This means that you should mentally assign a zone to the important textured shadow and highlight areas of the subject.