For diversions - Finding a rough heading.
Think of your present position as the centre of a clock face. Draw a mental line to where you want to go and think of it as a clock hand - Mentally give that hand a 'time' (Where it would be pointing on the clock face)
Multiply the 'time' x 3 and stick a 0 on the result and you get the heading. For example -
Imaginary line is in the '8' position, 8 x 3 = 24. Add 0 = 240 degrees
Line in '5' position. 5 x 3 = 15. Add 0 = 150 degrees