The recent market volatility points out the necessity of carefully managing risk both before you open a new position and after you already own it.
How do you manage risk prior to initiating a position? By proper sizing. That means the number of contracts or spreads traded should be appropriate for your experience and pocketbook. One easy method for reducing risk is to trade smaller size (fewer contracts).
Another method for reducing risk (it has worked far better for me than I could ever have anticipated) is described in The Rookie's Guide to Options. I have updated (Chapters 9 and 20) the free eBook to include some background information, plus some cautionary words about option strategies that involve unlimited risk.
If you already have a copy of the original eBook, feel free to download a copy of the newer version – available now. It has the same title as before, so if your computer tells you you already have a file with that name, it's okay to overwrite that file.