The testing process is quite similar to criminal investigation.
It's full of analysis, logical reasoning, true and false conclusions.
And the most interesting part is when we investigate bug which are difficult to reproduce. It could be a 'heisenbug' which is too hard to reproduce, or the bug from user with no description.
Trying to investigate this or that difficult bugs I want to learn from Sherlock Holmes, the greatest detective.
I'm going to tell, which of his approaces seems to be useful in testing. They could help qa engineers to investigate bugs effectively, with great interest and passion, and to say finally "it was elementary..."