Could you more experienced give me one bit of advice: How long do you actually do this? do you use the 24 hours to the fullest, drink thousand gallons of coffee and get serious sleep deprivation?
I used to stay up all night and skip classes the next day. Same way I wrote my papers. Four rounds of
that can be exhausting, let me tell you!
More helpfully, however, the first thing I would do is map out potential relationships between the ingredients. The resulting web would become a frame to hang the adventure on. I'd give myself some time to flesh out the ingredients and their relationships in my head, jotting down notes as I went.
I always tried to have the basic vision more or less complete before I began typing. That way, I could (hopefully) see if something wasn't going to work beforehand and not have to make significant changes while writing (an inefficient use of time and energy). I'd edit as I wrote, because that's just easier for me (and I'm compulsive that way).
Once written, I would read to make sure it was well-presented and made sense. Fix it. Read it again. Fix it again. And so on until it was as good as it was going to get, or I had run out of time.
(It may be worth noting that I put
way more effort into an IRON DM entry than a class assignment. This made me a much better contestant than student. But then, it was easier to get an A or B on a first-draft paper than win a round of IRON DM!)