Actually, I wrote:
Timing marks every 6 minutes may be added as must the exact elapsed time at readily identifiable visual fixes roughly corresponding to easy fractions of the way along the leg (to make proportional timing correction reasonably straightforward) and at the turning point.
which means put 6 minute marks on if you wish (I don't bother), but do put times against readily identifiable visual fixes. You don't need many of these (one about every 10-15 mins should suffice), but choose them at some simple fraction of the leg length - i.e. a nice obvious fix at 30% of the way along the route can be treated as 'about 1/3 way along track' for timing correction, whereas an exact point in the middle of nowhere at exactly 50% of the leg is pointless.
Also, for the terminally dim who still seem unable to read, once you've established where you are to make the 'miles off track' estimate, you turn back to track for the appropriate time. In the time you are chugging back towards track, double check the distance and jot down the timing correction. No need to add it up there and then, do that later. When you're back on track, then and only then check that the DI agrees with the compass, that the ball is centred and ask yourself whether your flying had been nice and accurate thus far. If the answer to any of those questions was 'no', don't bother changing your heading from the original once you're back on track - blame yourself. But if the answer was 'yes', then the wind must have been the culprit, so use your single drift line assessment to correct by the same amount. No silly reciprocal-of-the-fraction-flown-multiplied-by-the-drift-angle to do in your head - just a single figure to add or subtract. If it's more than 10 deg, the weather-guesser must have been telling porkies!
Why is track-crawling frowned upon? One reason is that you spend too long staring at the ground and not looking out around you for other aircraft!!