A trick from Physics. Where applicable try to decipher from words as many numerical facts as possible and then just write them down.
eg. A car is travelling away from S along the road at a speed of 100km/h. The distance from the car to S is x km.
the information gives us a speed, which we know is a change of displacement over change of time. So we can say
Also things like 3D trig, try to split it up into a series of 2D diagrams and once again find numerical data.