Bob,
I'm surprised you are not telling us how to do this as I understand you are from Germany. It's pretty simple and it used to be done from Germany in Luxembourg.
You establish a corporation in Luxembourg and do your business as a branch in Germany and your tax liability is in Luxembourg where the tax rate is lower, hopefully 0%. You repatriate your profit from Germany back to Luxembourg as a consulting fee. Let's say your profit for the year was $50,000. So you send it to Lux as a consulting fee and you no longer have a profit. You realize it in Lux and pay no tax. You either smuggle the cash back to Germany or just keep it in Lux and write checks off it.
This was good into the late '80's. I don't know if it works anymore there, but it always works somewhere. Globalization is not the friend of the small businessman. The key is to find a regime where they are willing to deal.
Whatever happened to Charles Taylor and Edi Amin?
It used to be that there was a thing called a foreign sales corporation also. You could keep your profits in it and not pay any income taxes on them and pay your expenses with it. You couldn't repatriate it directly. So you could probably pay your children's education, your vacations, your automobiles, your mortgage, pretty much everything except your salary. And if you wanted to go there and pick up some cash, you could probably do that.