Pirates do it better with grog - yes, that was me, in character for a game of Libertalia
The Effect Of Writing While Under The InfluenceSome writers prefer to write while under the influence of alcohol or drugs, as illustrated by this Guardian article "Why do writers drink?". Kerouac, Dylan Thomas, William Burroughs, Hemingway, F Scott Fitzgerald: they were all known to mix altered states of mind with creative work. Some of my writer friends have indulged in this way. Some of them still do. Some of them stopped, saying that as they got older it just made them tired - so now they only write under the influence of hot chocolate. Another told me she used to write while on speed: pages and pages of it. But it turned out to be drivel. One friend said he'd written his best ever short story while stoned - unfortunately he forgot to save it and it was lost forever. One common theme seems to be that it is a fine balance: too little or too much is disaster, but there's a cusp of creativity which works perfectly if you can attain it. Another common theme is that if you hand-write the draft, it may be unreadable the next day in the cold light of sobriety.
I prefer to write when I'm most alert, calm, and full of energy. That's usually in the morning, after my first cup of tea and a good night's sleep. I find it easier to arrange notes, consider plot points and beats, merge ideas into scenes, whilst sitting back and letting characters attain some independence. Writing for me is quite a cerebral act, juggling hundreds of ideas and phrases and trying to judge it so they land on the page in the most pleasing combinations.
Method WritingThe exception is if I'm trying to capture the experience I'm writing about. Some authors call this "method writing". So if I'm writing about someone getting gradually more tipsy while music is playing too loud then I might get tipsy while music plays too loud. Of course, you then need to edit-edit-edit the raw output to cut out the crap; embedded in the slush will be a few gems that enhance the finished scenes. They can be selected, extracted and polished when back in a normal frame of mind. Recording experiences is handy for getting a few key images or feelings that capture the experience in media res, and first-hand experience helps to avoid cliche. In 2000 Tunes one of the protagonists does a lot of drugs during a bad period in her life, so I could have a sub plot of her cleaning up her act. I'd had no experience with the drug in question, or with the sensations of snorting, so did experiments and recorded it all so I could use some of them as detail in the scenes. It's just another form of research. In that case research that made me sneeze a lot.
Option B: Partial ExperiencesThere are limits. You're after capturing the thoughts and sensations in order to escape from cliche and trite expectations, not replicating anything harmful to yourself or others. If you're writing about nearly drowning in an arctic sea you are not going to try it for real. But you might try climbing into an ice-cold bath for a partial experience of it. If you're writing about someone exhausted from a week of sleep deprivation and hunger you wouldn't replicate it exactly, but you might stay up for one night, or do a 24 hour fast to get an idea of what the character might go through. When I wrote Sinker (in They Move Below) I visited a loch at night so I could capture the sounds and smells and sights the main character experienced.
One of the problems with lazy writing (and something that leads me to get out my whip when I am working on a client's novel) is its habit of falling back on stock phrases and descriptions. They fail. They do not capture the essence of being in a situation. And when the showing fails, the writer has to fall back on too much telling, and we all know where that leads. Writing must be fresh. Otherwise what's the point? We've all eaten enough stale croissants for a lifetime, we don't need any more.