2D Sketches

For each iteration, you should make four 2D sketches. Make sketches for the front and rear suspension. For each of those, make one for roll and one for bump. The bump sketch only needs one side of the car (see below). 

The first step is to establish your constraints. The inner control arm points are determined by the size of the chassis. At the front, the minimum width of the chassis is constrained by the chassis templates. At the back, the minimum chassis width is constrained by the dimensions of the motor and powertrain mounting bracket. You want the lower control arm to be as long as possible to minimize the "scrub" of the tire when the car rolls. 

For the bump sketches, you can add the spring system, as well as the steering rack and tie rods. 

Pat Clarke video 

Plenty of great rules of thumb in this video. Watch it!