By Every sermon is different. The passage is different, and even if it isn’t, the church is different. As Peter Adam says, every sermon has a date and a postcode. Every time, it’s fresh.
But I’ve come to realise that although the result is different, the process for producing a sermon is pretty much the same.
Step 1, read through in several translations, and pray.
Step 2, break out a sentence flow diagram, and pray.
Step 3, press into the structure, and pray.
Step 4, consult relevant commentaries, books and study bibles, and pray.
Etc. etc.
Now this is simple and obvious, but surprisingly effective.
If I write in my diary, ‘Sermon prep,’ and block in 2 hrs, I make progress, but it feels vague. I don’t really know how I’m doing, as I move towards Sunday.
On the other hand, if I block in ‘Step one, 45 minutes,’ I get to see whether I’ve finished it or not. So I can move on, or reschedule.
And if I know that some steps routinely take 45 mins, max, then makes chunking the whole process much simpler. I’m no longer looking for a block of 3 hrs day after day, but identifying useable units and then getting a breather.
It also means that I can space the process more intentionally through the week. The blue sky stuff can happen while I’m walking the dog, because I’m not feeling itchy that I don’t have the sentence flow done yet
Now you might be the kind of person who works solidly for 3 hours without any visible prompts or support. But if you’re more, ahem, normal, and you think ‘I’ll just get this done, then I’ll grab a coffee,’ here’s the answer.
Chunk the process and reward your progress.
Hashtag that. It even rhymes. A bit.
ministrynutsandbolts.com 
Hi Chris, I’ve recently found this kind of thing very helpful. If I may share my process (as it might help others). I plan to spend two hours each day of a week (not necessarily in a solid block), 10 hours in the week in total (with time to spare if necessary) doing the following:
Monday: What does the text say? (exegesis; diagramming etc)
Tuesday: What am I going to say? (commentaries; summary statement)
Wednesday: How am I going to say it? (structure; applications; illustrations)
Thursday: Say it! (write a manuscript)
Friday: Prepare to say it (reduce manuscript to notes)
I’m not rigid with this, and sometimes jump ahead as something comes to mind. But having the structure has helped sermon prep to not be unnecessarily prolonged so there is still time for other things in ministry, even for those weeks when I’m preaching twice in a week!
Great, Jonny – thanks for sharing your outline.