Good stock picking is about doing your basic research and looking long-term. And knowing when to take a little money off the table.
I bought AAPL 10 years ago because of the long-term prospects (which many panned at the time). I sold off a quarter of my holdings after the Jobs cancer scare. Anyone who goes long-term in this stock has to keep in mind that if anything (God forbid) were to happen to Steve, this stock would tank 40% in moments. You cover yourself by taking some money off the table when you're up, using stop/loss orders that are say, 10% below the current price, and/or by buying cheap put options as insurance.
That said, AAPL can be played short term using options, but with all this interest that carries some hefty premiums. For example, I bought 5 July 100 calls back in April for $4.50. Sold 2 of them when they doubled, and have the 3 left (currently at $20). Now we see how greedy I can get by letting them ride.
For those that don't know how options work, they are a great way to play the stock with relative pocket change. You are either betting that the stock will go up (buy calls) or go down (buy puts). A call gives you the right to buy (or sell) the stock before some set date at a set price. Each call or put covers 100 shares, so you can "have" more stock than if you bought shares outright.
For example, those 5 calls I bought gave me the right to buy 500 shares at $100. At $4.50 each, that was an investment of $2,250 plus commissions. If the stock goes to $120, the options are worth about $20, a net profit of $15 in round numbers. (15)(500 shares) = $7,500 profit on that investment. In contrast, if you instead bought AAPL stock outright at $95, you could only have bought about 24 shares. At $120 that nets you $25 per share or $600 profit. A marked contrast!
Of course, if the stock went down to $90, or $80, the options could be completely worthless at or before expiration whereas you would maintain most of your investment if you had bought the stock. But your loss is limited to the amount you bet in either case.
There is another and less risky way to get into AAPL more cheaply than buying it outright. Buy deep in the money calls - for example, July $70 calls cost about $50 when AAPL is at $120. But because these are so deep in the money, their price fluctuation is almost identical to the stock price and not hypersensitive to a $5 dip as a $115 option would be. In short, you can spend $7,000 instead of $12,000 to control the same number of shares (100), and if the stock goes up your upside gain can be great.
One further elaboration is buying puts as insurance on the shares you own (this is really what options are for). Let's say, AAPL is at $120 and you own 1,000 shares. Your investment is valued at $120,000. You can buy July $100 puts at roughly $0.65. You purchase 10 of those as insurance to cover your investment for (10)(0.65)(100) = $650.
If AAPL stays at $120 or higher through the expiration on July 20, your puts (insurance) expire worthless. Not unlike that life insurance or auto collision insurance that you have. But let's suppose it turns out that the iPhone is delayed by a court injunction or something terrible happens and the stock loses a quarter of its value, plunging to $90 a share.
Without the covering puts, your investment went from $120K to $90K, a $30K loss. With the covering puts, your shares have the same loss, but your puts are now worth $10 each. So you gain $10,000 (less the $650 you spent as your insurance premium), and your net loss is only $21.65K. And if had ponied up $1,950 to buy 30 covering puts, your net loss would only have been that $1,950!
Wow, this is too lengthy already. Stop/loss is another way to lock in gains if the stock starts to tank. Look it up on any investment site.
Standard "not an investment broker/adviser, you may lose everything" disclaimers here. There are plenty of basic stock investing sites that discuss options in detail, and you should go read up on those before trying anything like this of course.