Painstakingly careful placement of each piece of broken glass. Instead of following the pattern of a 'tree', Magnus went 'free form' and created a very nice Fireplace with lots of interesting details.
Mom resisted adding her own ideas by purchasing her own kit and sticking to that. I was completely dismayed when I saw a mom not just supervising her children in this activity, but flat out doing for all three, their activity for them. This was for fun, not even for a 'grade' and yet... Seriously, she was doing their project for them.
Now I am the first one to fuss and want my kids projects to be 'perfect' but I have since learned to just get my own kit and be a perfect as I want on THAT and let the kids explore on their own.