Four craft movements plus a practice passage to record and listen back to. The technical spec lives on the ACX page.
Pace and the punctuation lie
craft[the page is not a score]
Beginners read the punctuation: a short pause at a comma, a longer one at a full stop, mechanically. Real speech does not work that way and the result sounds like a train timetable.
Pause where the meaning turns, not where the mark sits. Some commas want nothing at all. Some full stops want two full seconds because the idea before them needs to land.
Character without performance
craft[suggest, do not act]
For fiction, distinguish characters by rhythm and pitch centre rather than by accent or funny voice. A slightly slower, slightly lower read is enough for the listener to track who is speaking, and it is sustainable for eight hours.
Keep a note of what you did for each character. By chapter fourteen you will not remember, and listeners absolutely will.
Breath and mouth noise
craft[the two things editing cannot fully fix]
Breathe through the mouth, quietly, and take the breath a beat earlier than you need it. Panic breaths at the end of a long sentence are the loudest thing on most amateur recordings.
For mouth clicks: room-temperature water, a bite of green apple, and do not drink milk or coffee in the hour before. Clicks can be edited out one at a time, and on an eight-hour book you do not want to.
Hour six
craft[the sustained-attention problem nobody warns you about]
Energy drifts down across a session and you will not hear it happening. Record the first two minutes of each session, then listen to the last session's opening before you start, and match it. That one habit fixes most consistency problems.
Practice passage
2 min[record it cold, then read the notes above, then record it again]
The road out of the valley had not been repaired in eleven years, and every winter took a little more of it. In March the council sent a man with a clipboard. He stood at the bend where the tarmac gave out, wrote three lines, and drove back the way he had come.
"They'll not fix it," said Eileen, who had watched him from the gate. "They never do." Her son said nothing. He had come home for a week and had already been there nine days, and the road was the least of what was wrong.
[listen back for: the two characters distinguishable, the breath before the long sentence, the pause before 'and the road was the least of what was wrong']