Being one of my occasional random posts about playing music, for no better reason than that I feel like it. As (mainly) a guitar player, I hear a lot about learning particular licks, as if learning the best bits of other people's work is the only way to play well. As someone who listens to a certain amount of jazz and fusion, I also hear a lot about improv, about being in the moment and producing music off the cuff.
Now, neither approach is perfect. Learning licks has the potential to create musical clones, or worse, to create guitarists with no sense of melody. Their licks are invariably the quick bits, and they forget to put anything inbetween, like a painter forgeting to balance the space of the painting, or a writer! putting! everything! with exclamation marks! I hear a lot of metal solos that appear to have no connection to anything beyond the lead guitarist's practise regime. I've done it, as well.
As for improvising, well... can you improvise? That probably sounds weird, but not as weird as the answer, which I suspect is no. At least, I suspect you can't improvise completely. Even players like Robben Ford say that live, 80% of the time they're putting together things they've worked out in practise. And if you could improvise totally, I'm not sure it would sound that good. You'd lose most of what made you sound like you, and a lot of what made you sound musical. Just look at the weird end of jazz.
Perhaps one approach is to think more in terms of melodic lines than scalar or arpeggio based licks, like Carl Verheyen does. You still get to work things out in advance, but they're slightly more musical things. They're also more usable things. Far too many times I've sat down working through some complicated run, only to realise that it's something I would never use when playing.
Generally, I try to relate these musical posts back to writing in some way, and this is no exception. The area where this applies best is possibly in the plan v no plan debate, where I suspect the point is that, even if you think you're just writing, catching the flow, you've probably still got at least a vague mental plan, and you're working with ideas and influences that have been in you a while. At the same time, I think it also says something about using what might be termed stock elements. That is, the bits that are so common in a particular type of writing that they verge on the cliche.
Inevitably, some writers will put them all in by numbers, stand back, and then wonder why the result doesn't work (I've done that, too). Others will insist on complete, absolute originality in every little thing, and then wonder why their audience doesn't have a way into the piece. With the music, my suggestion was to work with melodic lines, but what does that mean here? Maybe following the story is the nearest equivalent. Write what it needs, and hopefully, neither extreme will come calling too soon. Although strange wide interval runs might, if Carl Verheyen is anything to go by.