Steering
Hold the wheel with both hands and turn smoothly. Sudden steering at speed unsettles the vehicle far more than the same movement made gradually.
Steering has play in it by design, but excessive play, a wheel that pulls to one side, or vibration through the wheel all mean something needs attention - usually tyres, alignment or suspension.
The steering works on the front wheels. It does not work through the gearbox, the engine or the brakes, and a fault in the steering cannot be corrected by any of them.
Look where you want to go. The vehicle follows your eyes more reliably than it follows your hands.