I actually had my brakes switched on all my bikes so my front brake is on the right hand side. I use both when I REALLY have to stop, but I hardly ever touch the back brake. No matter which one you use - panic grabbing can cause no end of problems but the more you work with the front brake - the more you'll learn just how far you need to pull to stop. You'll be surprised, you'll stop faster with less pull then using the back. and yes - during one of those OMG I HAVE TO STOP moments even without going downhill, I actually slide backwards off the seat so my weight is over the backtire (just in case).