"When we own portions of outstanding businesses with outstanding managements, our favorite holding period is forever."
-- Warren Buffett, letter to shareholders, 1988

Warren Buffett is arguably the most successful investor ever, and his investment philosophy is quite straightforward: buying high-quality companies and holding them for the long term, ideally forever.

Because of Buffett's successful and simple approach, many investors usually look among Warren Buffett stocks for investment ideas worth including in their own portfolios. Keeping this in mind, names such as Coca-Cola (NYSE:KO), Procter & Gamble (NYSE:PG), and Costco (NASDAQ:COST) could be interesting candidates for investors looking to replicate the moves of the master.

Coca-Cola
Coca-Cola is going through a difficult period lately. Consumers around the world are avoiding regular sodas because of their calories, and diet soft drinks are also under scrutiny because of the negative health implications of artificial sweeteners. In this context, Coca-Cola is delivering uninspiring revenue growth; organic sales volume increased only 1% in the last quarter.

Ko Pic

Source: Coca-Cola,

But the company has the resources to adapt to changing consumer habits. Coca-Cola benefits from unparalleled brand recognition in the industry, a gigantic global distribution network, and abundant financial resources to invest in areas such as marketing and R&D to bring new and healthy products to the market.

Management is implementing a series of initiatives to accelerate growth and increase profitability, including increased marketing investing in strategic markets, streamlining global operations, refranchising its bottling operations in North America, and expanding its productivity program to save costs, among other things. Coca-Cola intends to save approximately $3 billion annually by 2019, and it aims to sustain earnings-per-share growth in the high single digits over the long term.

It's worth noting that the company has proved its ability to produce consistently growing cash flows through all kinds of scenarios over time, Coca-Cola has increased its dividends for 52 years in a row. The stock pays a dividend yield of 2.9% at current prices.

Procter & Gamble
Procter & Gamble is another Warren Buffett stock that stands the test of time. The company has paid uninterrupted dividends each and every year since its incorporation in 1890, and it has raised those dividends for 58 consecutive years. The dividend yield is in the neighborhood of 2.9% at current prices.

This global juggernaut owns a rock-solid competitive position in several consumer-staples categories; the company sells mostly everyday necessities as opposed to discretionary items, which provides reliability to its cash flows through good and bad economic times.

Pg Pic

Source: Procter & Gamble.

Warren Buffett is all about competitive advantages, and Procter & Gamble's portfolio of brands represents an extraordinary source of competitive strength. The company owns 23 brands generating more than $1 billion each in global sales per year, including widely recognized household names such as Ariel, Gillette, Crest, Pantene, Pampers, and Charmin, among several others.

The company is optimizing its portfolio, selling underperforming brands to focus on its more attractive opportunities. Sometimes less is more, and a smaller portfolio could mean higher profitability and more dynamic growth for investors in Procter & Gamble.

Costco
When it comes to competitive strength in discount retail, Costco is second to none. The company makes most of its profits from membership fees, not margins on sales. That means Costco can sell its products at cost, or sometimes even at a loss, charging amazingly low prices for its products and keeping customers remarkably happy with their membership.

Cost Pic

Source: Costco.

Costco has a ranking of 84 in the American Customer Satisfaction Index, the highest one in its industry group, and materially better than the 80 assigned to Wal-Mart's Sam's Club, perhaps Costco's closest competitor. Customer retention rates are notoriously high, above 90% in mature markets such as the U.S. and Canada.

A smart business model and a satisfied customer base are being reflected in consistently strong performance from Costco. While most competitors are reporting stagnant sales, the company announced a healthy 7% increase in comparable sales, excluding the impact from gasoline prices and foreign exchange fluctuations in October.

As the company grows in size, it gains purchasing power with suppliers, which allows Costco to negotiate better prices and more favorable conditions. Besides, economies of scale generate additional cost savings as volume expands. The bigger Costco gets, the stronger it becomes from a competitive point of view, and that bodes remarkably well for investors in the company over the decades ahead.

Andrés Cardenal has no position in any stocks mentioned. The Motley Fool recommends Coca-Cola, Costco Wholesale, and Procter & Gamble; owns shares of Costco Wholesale; and has options on Coca-Cola. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.