Speaking of Buffett, his situation with Berkshire does have one major flaw in that having so much money to deploy, he's chosen to buy companies outright instead of merely taking minority stock positions. Owning 100% of a few companies might work, but how on earth can you juggle majority ownership of a dozen or 2 dozen companies? Bad idea.
Buffett is very careful in the selection process of which companies to buy, and keeps existing management, but this is a recipe for big problems as his 'stable' of companies gets increasingly unwieldy. In addition to his age (88), this is why I wouldn't invest in Berkshire itself. The wisdom of having so much in Apple stock is another question, and Buffett is increasingly relying on several younger stock pickers.
That said, Buffett's strategy of always staying long, while letting cash build up when you can't find compelling values, seems like a good way to approach stock investing. Better than trying to time the market, go short, etc.