Never pass a fragment off as a sentence. Fragments commonly occur when the writer fails to include a subject. The result is a clause or phrase that does not complete an idea (See Reference 1).
Example: He broke his leg on the trail. Cutting the camping trip short.
The second sentence here is incomplete because it has a verb but no subject. The word "trip" should not be mistaken for a subject because it is not the thing doing the cutting. One way to fix the sentence would be to replace the period after "trail" with a comma and start the next word with a lower case letter.
Use Subject-Verb-Object (SVO) construction. The object is the person or thing that receives the action. Including the object after the subject and verb clarifies who did what and shows the result of the action.
Example: She passed the test with flying colors.
Here, "she" is the subject, "passed" is the verb, and "test" is the object. Placing the sentence's primary elements in this order gives it a natural flow. It keeps the statement concise while conveying a sense of completion.
Write in the active voice, rather than the passive voice. Sentences in the passive voice turn what would be the object in an SVO sentence into the subject, thereby de-emphasizing the subject's role in the action.
Example: The drink was spilled by the bartender.
This sentence is in passive voice. Note that the bartender is not the subject even though she is the one committing the action of spilling the drink. Technically speaking, the sentence is SVO, only it has its roles reversed. Also notice that if we omit the words "by the bartender" the sentence is still complete. The problem is that reader doesn't know who acted.
The passive voice can be appropriate in situations where the person or thing committing the action is less important than the action. This is often the case in journalism.
Example: The earthquake could be felt as far away as Iron City.
Here, the intent of the story is to emphasize what happened and where. The writer is covering the earthquake as a whole, rather than its effect on the people in Iron City.
Keep your compound sentences from turning into comma splices. A compound sentence uses a comma and a linking word to combine two or more closely related clauses, each capable of standing alone (i.e., independent clauses). (See Reference 3).
Example: She was looking forward to a successful dinner party, her husband had other plans.
This sentence is a comma splice because there is no connecting word after the comma showing the relationship between the two clauses. Adding "but" after the comma creates a correct compound sentence. This clarifies and stresses the connection that makes it appropriate for the two ideas to be in the same sentence.