Where do people believe that normal working out ends and artificial assitance begins.
With the times puzzles I have different amounts of 'workings' out that I allow myself to do dependent on the difficulty.
i.e. Easy - pen must not touch paper other than writing the answers in and I have 2 stops on my train journey to solve them.
Medium - still no 'workings' allowed but the time scale is a little longer
Difficult - I allow myself to jot possible numbers in the margins of the paper, but usually don't have to.
Fiendish - anything goes in terms of pen and paper workings - e.g. redrawing grids with possible values etc. Then I copy it to a spread sheet and print out a larger version so I can see the pairings etc more easily. If I'm still not there I use some 'utilities' I've put together on my spreadsheet to highlight certain values etc. Finally (after a few days) I look on these boards and wait for Animator to drop the appropriate hints (thanks Animator!! ).
What are your self imposed 'rules' ?