Its not so difficult
Think of the whiz-wheel as a triangle of vectors. Draw a vector triangle, then see how is transposes itself to the whiz-wheel and it should help to understand it.
A. the aircraft position,
B. the end of the TAS and heading vector
C. the resultant position of the a/c.
Vector AB is the TAS and heading,
vector BC is the wind,
vector AC is the groundspeed and track.
Point A is an imaginary point at the bottom of the sliding scale.
Point B you mark yourself depending on your airspeed and heading, by sliding the scale, and turning the wheel to indicate the wind from direction.
Point C is the centre of the whiz-wheel.
If you are using the Wind Up method, then invert the meanings of points B and C. (point B is the centre of the wheel, and point C is the start of the wind vector)
After you have marked point B, draw the wind vector, it makes it all clearer.
Yes, I do use the whiz-wheel, as well as the electronic devices. Its a good fallback, and once you understand it, quick and easy to use.
GB.