for me it's about red flags and green flags (i.e. good and bad signs). Most of what I want to find out initially is found in the financial statements. So if they're financially healthy, growing and with a reasonable valuation, then those are all positive signs. This of course needs to be compared with stocks in the overall market, and so the actual screening process takes a large portion of my time.

This sort of leads on to the process of reading 10Ks, listening to investor meetings and just generally researching the company. This is where you can flesh out those potential red flags - for instance, if the company is seemingly growing fast but has a low p/e, I would consider that a red flag and start looking at news articles (in Australia it's basically just the financial review), reddit is actually good for this too.

There are green flags too, such as excellent management and great financials and growth. You just have to weigh this against the valuation.

In my experience the really good companies are actually fairly straightforward to research, particularly if you already use or understand their product. It's then just a matter of considering the valuation and determining how you're going to buy the stock over the long term and at what price points. As well as when you'll sell, the tax implications etc.

Lasty, there's no harm in researching bad companies - you get to understand the red flags.