On my skills test it was all a bit cruder than this, on the divert as mentioned above I found a landmark (a large town I could identify) drew a line from that to the divert destination, measured it with my pencil, rounded the numbers for speed/distance/time calculation and made an educated guess at the drift.
Just a little bit of mental arithmetic, at the end of the test the examiner isn't going to say you've failed as on the divert you were a minute or a degree out.
I hate the GPS bashing that goes on, "children of the magenta line"... "why bother to learn how to navigate" is all a bit patronising. People refusing to use modern technology like GPS, refusing to talk on the radio to anyone or use a transponder are the real danger.
Yes, we all need to know how to read a map and do dead reckoning etc, but why on earth talk down GPS systems? Years ago you'd pay thousands to have this technology, now there's no reason why every pilot wouldn't have it, other than their own arrogance.