After I had screened the startups for Nordic Angel Program at Slush, I conducted a little experiment: I re-reviewed those companies that I liked the most. My goal was to find out what common elements did these startups have that made me like the companies.
Once going through those startups that I like most based on the screening material (i.e. mainly based on pitch decks), I noticed that there were five things that popped out in most of those cases: Clear problem, scalable solution, great market opportunity, team diversity and sings of a product market fit.

Clear problem
I have always said that I am a simple investor, so show me a simple solution that I can understand. And having a clearly defined problem definitely helps that, so no surprise that a clear problem worth solving came up in all my top cases.
Scalable solution
No surprises here either: Scalability means the possibility to make the startup big. And that means opportunity for great returns for the investors.
Interestingly scalability took different forms in different cases, and that was actually what made some cases stand out: The startups were able to introduce a scalable business model into not so obvious problems. (Having a scalable SaaS business is a no-brainer but having scalability in a hardware business is a totally different game.)
Great market opportunity
Since I often invest in niche markets, I was not expecting to see the great market opportunity as a common element. But then again: Great market opportunity allows you to grow it big, so of course this attracts investor’s attention.
Team diversity
Teams with vision, product & technology know-how, sales skills and execution made it to my list. This was clearly a differentiating factor. There were a lot of startups with brilliant solutions, but the teams lacked driven people with sales skills.
Interestingly the size of the team did not necessarily correlate with the diversity: In some cases, a team of two was more able to cover the different skill areas than a team of four.
Signs of a product/market fit
Despite being early-stage startups, some were already showing signs that there should be a product/market fit. While a couple of early adopters does not yet mean a proven product/market fit, knowing that the company has already found someone willing to pay for the solution is a good indication that they are on to something.
Conclusion
I would say that the five elements above were pretty much in align with my expectations. In the end, all the elements are such that are addressed in more or less every article ever written about building successful startups. But still, for me at least, it was interesting to conduct this experiment by re-reviewing the startups I liked in the screening and see what common elements I could find.
But one needs to bear in mind that this was done based on the screening material alone. So maybe I need to do a similar experiment and see what kind of elements I am looking into when meeting the teams and analyzing the companies further.