How do I select companies and be patient enough to invest long term?

I choose a company by doing research. Information is so readily accessible for any business thanks to technology. I look at how the stock has performed, how stable the company/product is, their management team, their financial history, are some of the details to research. For patience with the long term, again technology allows constant access to watch the stock all day long, which makes it difficult to watch your investments drop. When the urge comes to sell to stop/prevent a loss you can see coming, you must force yourself to unplug, stop watching so closely and trust your research.