my solution: travel

1) you meet a lot of people while traveling (quantity)

2) you and them are out of context (and out of existing social circles)

3) all are a little bit more relaxed

4) you start pretty fast talking about things that are interesting without (social circle / insider) background information - you can filter them for quality (if they are interesting enough for do friendship follow ups)

from the last 5 years about 80% of the new people i now call friends i met during traveling