[zachthewf]

Taking a break and going for a run sometimes does this for me as well.

[loup-vaillant]

However, banging away at a problem for an afternoon is often needed for the solution to magically pop into our head next morning. The break helps, but so does the work itself.

[jonwinstanley]

Yes. Often need to rule out a series of initial ideas first.

[cutemonster]

Yes, and that can really feel like getting nothing done :-)

Or just spending time reading about the topic