The stock has run up significantly in 2013, almost 13% in just a few months, and from it's 52-week low in June of last year the stock has increased by nearly 30%. At the time of that low the dividend yield was 3.8%, almost a percentage point higher than the yield today. Selling call options can bring the effective yield back to or even higher than that level. With the stock currently trading at around $76.60, an $80 strike price would offer a 4.4% buffer against the option being exercised. This means that the stock would need to rise by 4.4% before the call option becomes in-the-money and the shares become at risk of being called away. The other component of the option is the expiration date. The longer the time until expiration the greater the chance that the stock price rises above the strike price, so we'll want to stick to fairly short-term options. Of course, the shorter-term the option the lower the premium, so there's a balance between safety and premium. The June $80 call option looks like it achieves that balance. The premium of around $0.53/contract/share leads to an annualized yield of 2.75%, which when added to the current dividend yield brings the total effective yield to 5.65%. If greater safety is required then the June $82.50 call option has a larger buffer of 7.7%. With this larger buffer comes a reduction of the premium to $0.18/contract/share, which knocks the total effective yield down to 3.8%. This, however, brings the yield back to the level last seen at the 52-week low. Chevron Corporation (NYSE:CVX) Chevron Corporation (NYSE:CVX) is one of the major integrated energy companies with a market capitalization of $230 billion. I called Chevron Corporation (NYSE:CVX) the best big oil stock in a previous article when the stock was trading at about $115 per share. Since then, the stock has risen by a little more than 4%, bringing the dividend yield down just below 3%. Chevron Corporation (NYSE:CVX) has grown its dividend at an annualized rate of 6.77% over the past 5 years, but has recently picked up that pace with an 11% increase in the beginning of 2012. Using call options, the yield can be increased even further without waiting for the company to increase the dividend. The June $125 call option has a strike price about 4.2% above the current stock price and a premium of $0.94/contract/share. This premium creates an annualized yield of 3.12%, which when added to the current dividend gives a total effective yield of 6.09%. This is more than double the current yield. Because the June $130 call option looks unappealing, the September $130 is a better choice if more safety is required. The premium of $0.95/contract/share represents an annualized yield of 1.49%, or an effective total yield of 4.46%. Although this yield is lower than that of the previous option, the buffer is larger at 8.3%. Wal-Mart Stores, Inc. (NYSE:WMT) For being one of the largest companies in the world Wal-Mart Stores, Inc. (NYSE:WMT) has never paid a particularly exciting dividend. After rising slowly over the past decade, the yield currently stands at 2.53%. WMT Dividend Yield data by YCharts Wal-Mart Stores, Inc. (NYSE:WMT)'s payout ratio (using free cash flow) is about 50%, meaning that the dividend growth will come mainly from earnings growth in the future. Given that this is a company which already does $469 billion in annual sales, I think growth is likely to be slower than in the past. With a lower yield than the other two companies I've discussed and expectations of slow dividend growth, Wal-Mart Stores, Inc. (NYSE:WMT) is not an ideal dividend stock. But selling call options can change that.