This is my analogy for writing along your merry way and then getting mired down in the middle, attempting to slog through to the end, and end up thigh-deep in the Fire Swamp or, as Jim Butcher aptly calls it, the Great Swampy Middle. Me, I feel like it's taking a big bite out of a peanut butter sandwich and having half of it stuck to the roof of my mouth as I struggle, gagging and scraping to get it out. (This is why I should depend on other people's analogies and not my own.)
But we've all been there and I've heard a lot of great advice about getting out. Here's some of the top picks:
1) Break up your routine: write somewhere new or at a different time from your usual habit
2) Get physical: take a walk, ride a bake, hike a trail, go to karate class: get oxygen to the brain
3) Do something rote: wash dishes, wash your hair, iron (bonus points for getting chores done!)
4) Switch your art: instead of writing, go to a play, a museum, listen to music, dance, sculpt, sing
5) Talk it out: a very understanding friend or critique partner is worth their weight in Lindt
6) Surround yourself with excellence: go to a conference, day event, or writer's workshop
7) For plungers, outline: go back and see where you're going & where you've been
8) For plotters, no-mind: shut off the brain and just dive in, knowing you'll cut back later on
9) Change gears: either skip ahead to a scene you know is coming or write a short story, song, or poem
10) Read: pick up a book that does what you want to do & does it well!
There. That ought to get the brain cells firing!
Whether it's a marker on a road map or a really big spoon, use whatever you can to get yourself out of the muck and keep writing! Have another one to share? Leave it in the comments. We all need a little help along the road to The End.
P.S. And if you haven't read Jim Butcher's incredibly generous informal guide to writing, I'd advise doing that for a start!