The custom pencil drawing of 2 little girls in an orange grove is going to take awhile. I can quickly scribble in the distant orange trees and have them be believable, but everything up close needs to be carefully drawn.

In order for the snow-covered mountains and the wind machine to show up, it needs sky. This is because you cannot draw white; you have to put shading around a white thing for it to appear.

You can see that the leaves on the trees are getting added to, and the distant hills and mountains are too. One side of the wind machine is darker than the other; this will require some attention. 

I think this drawing will have quite a bit of “put some on, take some off, put some on, take some off”. Sounds like a middle-aged woman trying to get comfortable, but I am talking about pencil here. I keep adjusting darks and lights in the distance, looking for the best way to make it look the most believable.