Ever got stuck writing? (Not as in writer's block)

Have you ever been writing something and, say, finished that thing you had planned and then you ask yourself "Wait...where do I go from here?" or "What now..."?

If yes, how did you deal with it?
If no, how did you avoid that?

I think it is not easily avoidable. The writer's block, in any form, is a normal obstacle for writers. When I have a block, I usually need a few hours, maybe a day, to distract and think about something else. Sometimes, the inspiration necessary to "break" the block comes unexpected, sometimes I just reflect on it and search calmly for a solution.

Anyway, distraction is important in writing: too much concentration does not give you rest, so your production may go worse and worse.

Have a pause when you want, read a book, play some games, go out for a walk (that is great for inspiration and thinking).

That's typically called "Painting yourself into a corner".

When I run into it, there's only a few things I ever do with it.  I either erase the last chapter or so (or whatever it is that causes me to paint myself into that corner) or I simply deem where I can't write anymore the "end point" of the story.  If there's nothing more to write about and you haven't left enough situations open or enough conflict still around, then your story is over when you reach that point.  There's no more to tell.

The only other thing you could ever do is simply ditch the story entirely because if it was so easy to paint yourself into a corner with it, perhaps it needs a massive reworking or it wasn't as interesting as you initially thought when you started it.

When I am stuck I find I have to back away for a set amount of time. I then have to be careful that I don't spend to much time away or it makes it hard to get back to work on a project.

I like to take breaks from a project after working on it after a three days worth of work on it. Then I take up to two days off. Almost like taking a weekend off of work. Helps me recharge, get ideas flowing, and best of all relax.

It doesn't happen to me very often. At least, the idea of where I need to go next is always clear to me. The story is already planned in point form before I start to write - my goals are clearly laid out before me.

That doesn't mean things go off without any hitches though, and I certainly run into bumps that make me wonder HOW I'm going to get where I need to go. For that, I mostly do what everyone else here suggested, take a break, step away from the writing to focus on something else and come back to it with fresh eyes and a fresh mind. It's amazing what an hour can do to your way of thinking.

Sometimes I'll consult other people who their opinions too. There's been many a time Rach (Yato now I guess) suddenly throws out five words of brilliant genius that gets me back on track. Bouncing things off other people is always helpful because they think different and can approach the situation from angles you might not have considered.

I avoid it by working in information I can work with later. So when I get to a point were that happens I can go "Oh, time to work with this information now."

By the time I'm done with that information, I have inspiration to keep going

Complex plots is the key

Like any true gamer, you work your way back through the map until you come to the last place the path diverged.

Or, you can just blow the whole damn thing up.

Seriously, chuck a grenade at your characters and see what happens. It doesn't have to be an actual grenade, obviously, but have something completely out of the blue happen, and see how your characters react. Sic a dragon on 'em. Make someone fall in love. Someone contracts a fatal disease. Someone comes back from the dead. Do something that makes your characters unable to even.

Goodness gravy, hello Hermes Trismegistus! :p  

I'm pretty much green in every relevant respect when it comes to writing. Everything I do with regards to human relationships and dialogue is stilted and horribly obtuse- so I have consigned myself to the abyss of non-completion: IE conceptualizing the story. 

For what it's worth, I try to only write when I have the mood on... That being said, I'm generally never any good at setting up the sequence of events, merely the events themselves that populate the storyline deprive of context and vitality which the characters provide.

What I can say is that often times we think of our stories as 'closed systems' in which a given set of interactions dominate the potential arcs that inhabit the sphere. When I reach this point where I can no longer fill in, I attempt to situate that sphere within a larger one- or broaden the scope of what was once 'the whole point'. In that way, you can even start manipulating the previous experience in terms of the new one- dropping a huge plot twist perhaps.

First, I take a big, long break and clear my mind. Have a day off. Play some Smash Bros., have a few ciders, re-marathon Firefly... Just laze about until my brain starts rejigging itself and gets back in the zone. Sometimes, the best thing you can do is just to come away for a bit.

If I'm still having difficulty after that, I'll re-read what I've written after a bit of time off and see if I suddenly have a Eureka moment that gives me an idea to move the plot along further. Not the most precise advice, I admit, but it works for me.