One likely will not have needed the future perfect in one's entire life. Unqualified superlatives are the worst of all. Avoid all that colloquial stuff. If this were subjunctive, I'm in the wrong mood. Writing carefully, dangling participles must be avoided.
Verbs has to agree with their subjects.
Take the bull by the hand and avoid mixed metaphors. Proofread carefully to see if you any words out. Everyone should be careful to use a singular pronouns with singular nouns in their writing. Steer clear of incorrect forms of verbs that have snuck in the language. Avoid run-on sentences they are hard to read.