to lock and try to drive off slowly and evenly, then unlock it again. the lock function is only made for driving at low speeds and only for a short period of time.
don’t power up while driving uphill. brake even lighter when going downhill.
in slippery conditions it’s a good rule to have a safe distance to the car in front of you. the car ahead might come to a non slippery part of the road, brakes and then you won’t have the chance to stop the car in time if you are driving on ice.
make sure you are at a comfortable speed before you reach a bend or a curve 