You have to spend a lot of time visiting companies, talking to company management, and reading over their financial reports. If you are a full time fund manager, you can do that. If you have another day job, don't use Buffett's method.
For beginners, best method is CANSLIM. Read William O'Neil's "How to Make Money in Stocks". If you can find, read the 1st or 2nd editions. The 3rd edition is not as good.
After a few years of experience, you can start to develop your own method.