Ask HN: Effective communication methods with remote employees.

We have a startup in Germany, which should work with their employees remotely. It's a startup, doing online paid services for foreigners willing to come to Germany. We have employees for each country, native speakers, and it's very hard to find all of them in one city to be able to work in an office space. Therefore we can only work remotely. But we can't communicate, solve problems properly and effective online. We hired some of them from their country, thousands kms distance from Germany. When we hire, we must explain the workflow which is very hard explaining it online. We used:

Trello Skype Mobile tel Complex explanations are drawn in Photoshop(!!!) sent via emails

None of them were useful and everytime when I hire someone I try to fly there and explain the work etc. Can you please list your favorite tools communicating your remote employees. This thread can also be used as a reference for others having remote employees or freelancers.