Don't wear boots while riding a bike.
I was trying to drift my bike on my driveway last year, since I managed to do it by accident. First and only try: As I tried moving my left leg into position, my boot (the top) got caught by the pedal and wrapped around the gears, instantly stopping the bike. I knew if I didn't change my inevitable flight pattern, I'd fly headfirst over the five foot high concrete wall, which probably wouldn't be good. I forced the back tire over so the bike would fall, and I skiied to a stop on my leg instead. I limped all day lol