Trying to think what I do...
OK, I do an essay map with a pen and paper. Mr Google says it is a mind map style, this is news to me...!
I guess I do all the editing/rearranging at that stage, then just bash the writing bit out fairly rapidly. Then I print out, read for typos and let DH (not scientific but v pedantic
) have a look at it, we scrawl in pen any edits, back to the computer, edit and send send send.
Oh - the word count limit is usually quite tight so I assign word counts to each section when I do the plan; if I'm close to the word count and have all my points in, then that section's done, full stop.
I probably take about 5-6 hours total for a TMA essay like this, and I am a crappy typist. Usually score around the 2:1/1 borderline.
Definitely worth having a go at the essay-plan-then-dive-in, I reckon, esp if your course lets you substitute your lowest-scored TMA; you'd have very little to lose. And about 20 hours to gain 