- Strong team (10 years friendship, history of working on interesting projects together)
- Proven determination (6+ tough years working on startups, willingness to travel from Australia just for the interview)
- Good primary idea + several other solid ideas (our primary idea wasn't a new concept at all, but a new, niche angle on a very established concept)
If you didn't get picked, it's because you didn't convey these qualities well enough. All you can do to get yourself there eventually (either into YC or to startup success some other way) is to keep persisting.
The key attributes YC looks for are smart & determined. You need to prove that you have these qualities, or if you don't, you need to develop them.