HEAD DESK: Can you write without a plan? What's your process?

We know this isn't
 an author like me,
because he's wearing a suit,
not a robe and slippers.
But, his desk looks like mine.

 HEAD DESK moments. Can you write without a plan? Well that's a good question.

Sure. I guess. But can you finish the book without a plan ? is a better question. Every book I've written started with a spark of an idea, an impression of

a scent or vision or emotion. Hmm, one of my senses was involved. Then it evolved with a variety of scenes and characters.

I remembered I needed conflict to challenge these people in their everyday world. I gave them that. I gave them a background and a growth arc, and still while writing, at the 75% mark in my books I stuttered to a stop. I knew the end, or  so I thought. Now how to get there. Sounds simple enough, right? But the essential link wasn't there. 

The characters were right there, in place. They encountered the final conflict...

Ah, perhaps this is the problem. Doubt?

Have I truly arrived at the final conflict? Will my characters find a way to resolve it satisfactorily for the reader? Will it be exciting? Will it wrench the heart and tie the readers' insides in knots before the satisfying conclusion. Can I create the imaginary stairway that will entice the reader to take that leap of faith and make a run for the finish line? Dive in--fight the battle with the characters?

Good grief! At my three quarter mark I stop and mull over everything before moving to the conclusion. This is where I determine if I can tie up all my loose ends, where I question the story's continuity. After writing all this, will I be able to transit the life my characters had before to what is about to happen to them. And then, will there be a happily ever after?

I'm learning that planning plays a big part in writing, and even if you successfully write by the seat of your pants, you probably have the plan in your head all along. You see the story all the way through--lucky you--step by step, scene by scene. I get stalled because I'm still planning in my head when I start--seeing changes in my mind at that elusive creative moment right before I wake, instead of working them all out on paper or keyboard early on. There's a lot to be said for a detailed synopsis. Writing it before instead of after suddenly makes sense. If you decide to change something along the way, go back to the synopsis and work the changes out there. It'll be easier than doing a major rewrite on the novel.

 In conclusion, every author has his/her own methods and processes. What works for me may not work for you, and so also the reverse is true. Will you share your process? Have you encountered problems and found solutions to deal with them?