Raff was an extremely hard worker. Having grown up the eldest of a large, poor family in provincial Switzerland and been subject to a harsh educational regime, Raff knew all about the work ethic. Once he decided to become a professional musician, life became so difficult that Raff was bankrupted and continued to be pursued for unpaid debts for another decade - even being thrown into gaol in Wiemar for an old Swiss debt. He discovered that a continual supply of piano pieces for his various publishers helped to keep him solvent and this "brotarbeit" habit stayed with him for the rest of his life. It would be wrong to assume from the number of works which he produced, however, that Raff found writing music easy or that he took little care over the finished work. Quite the contrary, Raff produced a large oeuvre because he worked very hard over many years. Like the French opera composer Massenet, with whom Raff shares many of the same unfounded accusations of easy uncritical facility, he developed a rigorous regime of ordering his day to ensure that he had sufficient and regular time to compose. This determined self-discipline was one of Raff's strongest compositional traits. It was especially important once he moved to Wiesbaden and took up teaching posts in two girls schools as well as holding private piano classes; and even more so later when he moved to Frankfurt as Director of the city's new conservatory.
During 1877 at a time when Raff was heavily engaged in setting up the Conservatory, he discussed his method of working with the American composer and disciple of Liszt, Otis Boise (1844-1912): "Before I begin to write continuously, I write down on small scraps of paper my main theme and in addition the second theme, also any particular trumpet and horn motifs, consider which roles they have to take on in my concept and then I clothe my intended work in instrumental colours, avoiding particular instruments if possible. It is practical to use those instruments which are usually found in the orchestra. Works which demand remarkable instruments are seriously handicapped. They comparatively rarely come to performance. If I have prepared my material, I don't get up from my desk, until the design of a whole movement is accomplished. A piece on which one works continuously can become a fundamentally flowing composition, but not if the thread of thoughts is frequently interrupted. After the outlines of a piece of music are once fixed, filling and colouring can last for weeks".
Raff took extraordinary care in the fashioning of his thematic material - particularly so as, for his time, he treated an unusually large amount of it contrapuntally. For example, each theme in each movement of his Piano Concerto is worked out in double counterpoint. A criticism , which is levelled with some justice, is that all this care still sometimes produced banal material which Raff seems to have been incapable of distinguishing from the glorious melodies he often created.
Even his severest critics acknowledged that he was a master of exciting and effective orchestration - the art of "filling and colouring" as he called it. Studies have made clear that in this area he was influential on Mahler and Tchaikovsky. The attention which he paid to the structural element of composition is underlined by his regard for architecture as second only to music and before literature and painting as an art form. Modern critics have suggested that Raff's immense technical skill itself could lead him astray. In his more mundane works he appears to have relied overmuch on tried and trusted recurrent rhythmic patterns, and harmonic or melodic progressions with the result that any tension in the work is lost, interest is lost and it becomes merely humdrum.
Raff's musical draughtsmanship was impeccable - he served as a reluctant copyist for Liszt for five years. He wrote out all the parts of a score himself - something about which Brahms was disparaging; but it is an indication both of the seriousness of his craft and his capacity for hard work.