One somewhat extreme yet effective solution to this is to get into situations where no one knows anyone and where there is some shared hardship involved. We di

One somewhat extreme yet effective solution to this is to get into situations where no one knows anyone and where there is some shared hardship involved. We did this by moving to another country where there was limited potential to really integrate into the local community (Thailand). Because expats existed in their own little community and everyone walked off the plane knowing no one all the new comers are extremely open to forming new friendships. At to this that moving to another country is a challenging experience which you are going through together and there is a very high potential for making a whole new group of friends. The only similar equivalent I can imagine would be something like joining the military. Everyone shows up knowing no one then they all undergo a series of challenging experiences together. It is not surprising that some military people seem to form lifelong bonds with their peers. Meanwhile if you stay wherever you usually live, an environment relatively lacking in hardship where everyone else has at least a semblance of an existing social network, making a whole new social network is extremely tough.