How to make best use of duoling
I assume it is best to "follow the star" and that you go back to master topics later on?
My standard practice working through the tree was two reviews to one lesson. Now that I am doing the reverse tree, I am doing only one review per lesson, as I am revisiting material I have seen before. But I now have an old fashioned grammar workbook to master concepts that Duo. has not taught all that well.