Slippery conditions will depend on your car... But if you have ABS on a dry road, just push stomp the pedal down. If the ABS isn’t kicking in, push harder. Also, straighten the wheel. Braking and turning requires a very delicate balance... i.e. experience and not panicking. So brake or turn, but not both.

On snow, I recommend instinctively knowing what to do. If you aren’t already experienced with handling your car at its limits, I’m not sure what advice would even be useful. "Just apply brake, steering, and accelerator input, all at the same time, in exactly the right amounts." Manual transmission? Downshift while doing all of the above