[logfromblammo]

To write a page of fiction, write ten pages of fiction, and then remove the nine that no one wants to read. Do all this entirely on your own, while working your day job.

To write a page of math, write a paragraph of math, illustrate it or insert the proof, typeset in LATEX, and leave the rest as an exercise for the readers. The readers will probably be your students, that bought your book because you required it for the course, and will make revision suggestions during class or office hours. Get a colleague to proofread for you, as you will proofread their math. Collect your pay for teaching and/or researching math while writing the math.