The safest is to buy deep-in-the-money LEAP calls with a delta ~ 90. I sometimes like to buy those instead of straight shares because they provide added leverage and you can also use them for call writes. It's a a good trade and one of the safest options strategies.
http://www.investopedia.com/articles...#axzz1idNCKUJ0
With that being said, you're not going to get rich with that strategy as it's a fairly conservative play with a limited downside and upside. It also requires more of an outlay than other options strategies.
I also like to occasionally buy SPY puts to hedge my long positions whenever I anticipate a dip in the market. When that happens, it's usually based on something I read in that weeks Economist. Nothing to fancy.
When trading naked puts and calls as your primary trading strategy, you should really get set up with Level 2 quotes and learn how to read them. It's fairly simple and really helps you squeeze the most out of each trade.
Other than that, don't hold too long b/c time decay will eat them up. When I get the SPY puts, I usually buy a month or two out and never hold for more than 3 days.
If you're waiting for a catalyst (such as the announcement of Phase III test results or an FDA announcement for a biotech), there's usually a run up beforehand, but be careful with that if playing small caps (like a biotech) b/c the big funds can get tricky in manipulating the prices.
Also, don't trade naked options on triple leveraged ETFs.