Determination of Lewis Dot structures and visualization of the shapes of molecules using VSEPR theory is an example of an abstract concept that students often find difficult to learn. I have found it useful to have a single worksheet/packet that my students can add to as we cover Lewis dot structures, resonance, VSEPR shapes, polarity, and intermolecular forces.
In an effort to align an old VSEPR lesson to NGSS, I told my students that we were going to look at the data available from the real molecules on the pHET simulation we were using and specifically look for patterns. Finding patterns is a cross-cutting concept; one of the three dimensions of NGSS.
Lauren Stewart discusses why she is having her students build 3-D models BEFORE teaching them to draw Lewis structures.