A method I've found useful for breaking the block.

[Foolish Frost]

Sit down with a blank page, and write the following sentence.

"The author sat in front of their typewriter and stared at the page. Nothing would come to them, and the words refused to flow. Frustration filled their mind as they began to scan the room for anything, anything at all, that would distract them from their useless pondering.

And then they saw it."

Proceed to find something in the room. Doesn't matter what it is. Describe the story author describing the item. Reread what I just said: Describe the author... describing the object. Don't even try to be poetic, or use good grammer. Just write.

"It was a jar. The label around it was only partially readable at this distance, but the part he could see said Nutritional Facts. It was made of cheap, mass-manufactured glass and was filled with golden wrappers, each containing a small candy that the author wanted desperately to taste at that moment. Each candy was a butterscotch, and would leave a creamy sweetness on their tongue if they would just get up from the desk, give up on the efforts to write, and reach for it."

Now... Go back to your book and start writing. If you feel yourself freeze, find a scene from the book you know you're going to be writing in the future, and jump to that. It's always possible you're not suffering from writers block, but just need to have time to figure something out about the scene you're in. There is no crime in writing important scenes out of sequence.

But hey, what do I know. I'm just an old fool.

 

[Bitterboots]

Now I'm dying for butterscotch.

 

[NicoleAisling]

This technique always makes me think of the movie Finding Forrester. The main character's mentor has him start writing by copying the very beginning of a short story and then veering off to make his own story.

 

[wannawriteJr]

I love (and constantly use) the "write an exciting/more interesting scene" idea.

Another idea, especially for the more difficult scenes that keep getting pushed off or scenes that can't be skipped because they impact what comes next: Just write out what happens as if you're telling a friend about my book. For example, Jane went into the room, and then the lights when out and she heard a humming, and then she freaked out...
It's obviously not what's going to end up in the finished draft, but it helps get past the block and frustration and allows me to write through difficult scenes.