Easier to mock than help apparently.
Whilst teaching a relative to drive, I aquired a number of large cones (cones with sticks would do), arranged them in a long line in an industrial park (Sunday), then just got her to reverse back along them repeatedly. Drive forward in the same pattern just to note the movements in reverse.
Once you have a sense of space around the car and the hang of turning the wheel, then the technique of parking is easier.