Use active instead of passive voice. One of the most common manifestations of bad writing is overuse of the passive voice. In English, the most basic sentence structure is S-V-O: Subject-Verb-Object. “The zombie bit the man” is an example of this sentence structure. The passive voice can cause confusion by putting the object first: “The man was bitten by the zombie.” It usually requires more words and use of a “to be” verb form, which can suck the energy out of your writing. Learn to avoid these constructions as much as you can.Using the passive voice isn"t always bad. Sometimes there is no clear way to make a statement active, or sometimes you want the lighter touch a passive construction allows. But learn to follow this rule before you start making exceptions.
The main exception to this is science writing, which conventionally uses the passive voice to put the emphasis on the results, rather than the researchers (although this is changing, so check the guidelines before you write). For example, “puppies fed spicy dog food were found to have more upset stomachs” puts the emphasis on the finding rather than the person doing the finding.