I digitize different habitats in one nature reserve. There was 40 ponds - I use "add circular string" option to give them a nice rounded shape. When I finish this 40 ponds I was instructed also to do as a separate part of that layer - area surrounding these 40 ponds as "Early successful grassland". Now, is a question - how I can "clip inside" of this polygon "Early successful grassland" these rounded 40 ponds? I found that option "add circular string" is not supported when I try to use this option together with options "Add Ring" or "Fill Ring". How I can add to the polygon a nice rounded and filled rings? Currently I use QGIS 2.18, but I check also new version of QGIS 3.0 and there was also missed connection between those features. I try use also Freehand Editing Plugin in QGIS 2.18, but there was also missed connection between features "Add Ring" and "Fill Ring". Is it there some kind of solution for this problem? I add picture to show how it looks like.