I hope you do not mind me using this thread to add something, simple though it may be. Pliny the Younger wrote a letter to Baebius Macer concerning the writing habits of his uncle, none other than Pliny the Elder, which I thought interesting for its possible insight into ancient compositional techniques. This is epistle 3.5
I was delighted to find that you are so zealous a student of my uncle's books that you would like to possess copies of them all, and that you ask me to give you a complete list of them. I will play the part of an index for you, and tell you, moreover, the order in which they were written, for this is a point that students are interested to know. "Throwing the Javelin from Horseback," one volume; this was composed, with considerable ingenuity and research, when he was on active service as a cavalry lieutenant. "The Life of Pomponius Secundus," two volumes;--Pomponius was remarkably attached to my uncle, who, so to speak, composed this book to his friend's memory in payment of his debt of gratitude. "The German Wars," twenty volumes;--this comprises an account of all the wars we have waged with the German races. He commenced it, while on service in Germany, in obedience to the warning of a dream, for, while he was asleep, the shade of Drusus Nero, who had won sweeping victories in that country and died there, appeared to him and kept on entrusting his fame to my uncle, beseeching him to rescue his name from ill-deserved oblivion. "The Student," three volumes, afterwards split up into six on account of their length;--in this he showed the proper training and equipment of an orator from his cradle up. "Ambiguity in Language," in eight volumes, was written in the last years of Nero's reign when tyranny had made it dangerous to write any book, no matter the subject, in anything like a free and candid style. "A Continuation of the History of Aufidius Bassus," in thirty-one books, and a "Natural History," in thirty-seven books;--the latter is a comprehensive and learned work, covering as wide a field as Nature herself.
Does it surprise you that a busy man found time to finish so many volumes, many of which deal with such minute details? You will wonder the more when I tell you that he for many years pleaded in the law courts, that he died in his fifty-seventh year, and that in the interval his time was taken up and his studies were hindered by the important offices he held and the duties arising out of his friendship with the Emperors. But he possessed a keen intellect; he had a marvellous capacity for work, and his powers of application were enormous. He used to begin to study at night on the Festival of Vulcan, not for luck but from his love of study, long before dawn; in winter he would commence at the seventh hour or at the eighth at the very latest, and often at the sixth. He could sleep at call, and it would come upon him and leave him in the middle of his work. Before daybreak he would go to Vespasian-- for he too was a night-worker--and then set about his official duties. On his return home he would again give to study any time that he had free. Often in summer after taking a meal, which with him, as in the old days, was always a simple and light one, he would lie in the sun if he had any time to spare, and a book would be read aloud, from which he would take notes and extracts. For he never read without taking extracts, and used to say that there never was a book so bad that it was not good in some passage or another. After his sun bath he usually bathed in cold water, then he took a snack and a brief nap, and subsequently, as though another day had begun, he would study till dinner-time. After dinner a book would be read aloud, and he would take notes in a cursory way. I remember that one of his friends, when the reader pronounced a word wrongly, checked him and made him read it again, and my uncle said to him, "Did you not catch the meaning?" When his friend said "yes," he remarked, "Why then did you make him turn back? We have lost more than ten lines through your interruption." So jealous was he of every moment lost.
In summer he used to rise from the dinner-table while it was still light; in winter always before the first hour had passed, as though there was a law obliging him to do so. Such was his method of living when up to the eyes in work and amid the bustle of Rome. When he was in the country the only time snatched from his work was when he took his bath, and when I say bath I refer to the actual bathing, for while he was being scraped with the strigil or rubbed down, he used to listen to a reader or dictate. When he was travelling he cut himself aloof from every other thought and gave himself up to study alone. At his side he kept a shorthand writer with a book and tablets, who wore mittens on his hands in winter, so that not even the sharpness of the weather should rob him of a moment, and for the same reason, when in Rome, he used to be carried in a litter. I remember that once he rebuked me for walking, saying, "If you were a student, you could not waste your hours like that," for he considered that all time was wasted which was not devoted to study.
Such was the application which enabled him to compile all those volumes I have enumerated, and he left me one hundred and sixty commonplace books, written on both sides of the scrolls, and in a very small handwriting, which really makes the number of the volumes considerably more. He used to say that when he was procurator in Spain he could have sold these commonplace books to Largius Licinus for four hundred thousand sestertia, and at that time they were much fewer in number. Do you not feel when you think of his voluminous writing and reading that he cannot have had any public duties to attend to, and that he cannot have been an intimate friend of the Emperors? Again, when you hear what an amount of work he put into his studies, does it not seem that he neither wrote nor read as much as he might? For his other duties might surely have prevented him from studying altogether, and a man with his application might have accomplished even more than he did. So I often smile when some of my friends call me a book-worm, for if I compare myself with him I am but a shocking idler. Yet am I quite as bad as that, considering the way I am distracted by my public and private duties? Who is there of all those who devote their whole life to literature, who, if compared with him, would not blush for himself as a sleepy-head and a lazy fellow? I have let my pen run on, though I had intended simply to answer your question and give you a list of my uncle's works; but I trust that even my letter may give you as much pleasure as his books, and that it will spur you on not only to read them, but also to compose something worthy to be compared with them. Farewell.