Build enough understanding that the solution feels inevitable afterward.

There is a point in understanding something where the answer stops feeling like a clever discovery and starts feeling like the only thing it could have been. That feeling is a reliable sign you have got underneath the problem rather than around it. Solutions that still feel like tricks usually rest on something you have not yet grasped, and they tend to fail in ways you cannot predict.

When you find a fix, keep going for a little while and ask why it works. If you can explain it so that it sounds obvious, you have understood it. If you cannot, expect to meet the same problem again in a different costume.