I've been an active investor for over 10 years, mainly focused on companies in the fields of technology and engineering. I basically look for three kinds of opportunities:
1. I mostly look for deep value situation were a lot of bad things have happened and lot of good things can happen (this might be Joel Greenblatt citation).
2. But I also believe that sometimes it's a lot better to buy a great company at a fair price than to buy a fair company at a great price to cite Charlie Munger here. So I regularly buy companies like Microsoft and Apple when the price is right, both of which are excellent companies.
3. I look for companies that understand how the media works and are able to produce a continuous flow of good news and have credible backers - the best example I can think of here is Tesla.
If I have to think hard about buying something or not, I don't buy it . I don't post articles often, but when I do I strongly belief what I write.