Hiffernan epitomizes the shady moralless hack type. He seemed to dabble in a little of everything as a writer. He wrote plays, poetry, Latin verse, periodicals, translations, and worked as a "pamphleteer and paragraph writer". He only ever achieved moderate success at best. The DNB explains, he kept "the friends on whom he sponged through dining, subscription collecting, hawking his books, and occasional blackmail. He wrote only when reduced by absolute necessity." Towards the end of his life, he relied on the charity of Foote, Garrick, and others to survive.