Quote Originally Posted by pdeeh View Post
How does one acquire sufficient experience in order to start mixing developers oneself?
Familiarity with metric measurement.
Knowledge of the hazards of the chemicals used. Read the MSDS for each one.
Ability to follow a formula accurately.
A high school (or better) knowledge of chemistry is helpful. Spelling is important. Sodium sulfite is different from sodium sulfate or sodium sulfide.
Coomon sense, if you don't know what you're doing then stop!