Don't bore the audience with sameness. Good writing relies on nouns and verbs. Some people have the misconception that their writing will be better if they use a lot of descriptive additions. This misconception may come from the elementary and junior high years when English teachers were trying to get their students to write anything beyond the monosyllabic responses generated by bored writers. The best writing, however, relies on nouns and verbs.
Good writing is mechanically clean.
Mechanical inaccuracy causes embarrassment and eliminates opportunities for jobs and promotion. While that statement sounds strong, it is true. Mechanical correctness cannot be left for someone else to check. Access lessons and on these types of errors at the Grammar area of the site. If English is not your native language, you might want to visit our online section for ESL students.