You've messed up several shorts by your own admission. I never used these occasions to tell you you'd been hurting other people though!
When I mess up shorts, it is usually through stupid compulsive trades. Addictive behaviour. There was one exception where I felt sure enough to advertise my prediction on the forum. Bitcoin was at $790. I said go long until $815, and then short Bitcoin. This is what I did, but an inexplicable (in my mind) surge of buying power took Bitcoin up to $835. According to rpietila, he initiated the panic buying surge when he make a large purchse on MtGox, in order to get his funds out. He reckons that he sat back in amusement as other whales panic bought on Gox, with the other exchanges following. Since then, Bitcoin has never been so expensive which proves my assertion at the time, that these were pretty fucking dumb buy-ins.
The flip side of that trade (just 2-3 weeks ago), is that if someone had more of a long term mentality to swing trading, an never had a Stop Loss triggered at $820 (like I did), then they would be now quids in on that trade. Like I said, There have only been rare instances when I have been cheer-leading the wrong side of the trade.
I aint shorting anymore. I woke up one day and decided that I didn't trust Bitfinex as a trading platform. Subsequent events have proven my suspicions founded on that one as well.