To make a sentence clear, make sure that dependent clauses and limiters are closest to the words they modify and do not use unclear pronoun references.
Example: After opening the refrigerator, it shut down (The refrigerator opened itself?).
To clarify, make the subject of the independent clause the same as the subject of the introductory clause.
After opening the refrigerator, I heard it shut down.
Watch the placement of limiters; they change the meaning of the sentence.
Example: Only I go to school on Wednesdays (No one else in the world does).
Example: I only go to school on Wednesdays (I do nothing else on that day).
Example: I go to school only on Wednesdays (I go to school on no other days).
Avoid pronouns without references.
Example: There is a problem (Where is a problem?).
Example: It is clear that a problem exists (To what does "it" refer?).
To avoid unclear pronoun references, remove "there" and "it" when they refer to nothing.
Example: A problem exists.
Example: Clearly, a problem exists.