Times under 100 seconds
I just posted a monthly score of under 100 seconds for the first time. I did not do all the puzzles this month, however. I did any 4x4 which came up, and also any 5x5 with an 'average solve time' of under 4 minutes 25 seconds. My normal time for a puzzle in that category is around 75 seconds, and the inevitable mistakes and brain cramps create a certain variability. As the end of the month approached, it was exhilaratingly stressful, because I knew that a poor score would throw the average up far more than a good score would bring it down.
In this subset of puzzles my insight is: if the clues were in the most efficient order one could write the solution down very quickly. So I go hunting for clues which address certain areas of the puzzle. In the 5x5 puzzles with low average times, focusing on the clues which give information about the top left hand category seems to be the fastest.
There are certain 4x4 puzzles that I have seen the path efficiently - my best time is 32 seconds.