Sqwiggle helps (seeing the rest of the team's faces) but it's a hard sell to convince others to use it.
Assuming of course you live in a somewhat business-hopping city. If you do, the monthly cost is a no-brainer for the productivity gain of having other people around, having a physical workspace, and a reason to leave the house.
That is an issue. In the UK outside the largest cities coworking spaces are few and far between. I will continue searching...
It can just be an office/studio that you share with others too.
Another option is to find existing companies. For example, maybe a design studio could let you use an office, or a desk.
--Matt @ WFH.io (https://www.wfh.io)