Skull drawings for fun!

WHAT do I do with the bottom? I have a few ideas.. but I don't know.......

Tank concepts I doodled. inspired by a WW2 book I’m reading about 4 guys in a tank in Libya.

These are robot concepts I did. The idea is that they roll around on these spheres and when they are stationary, they put down their feet. the drawing shows them with their legs down.

asian house concept.. incomplete

I was excited to get another mountain painting done (i love mountains) and I came to this. Which I'm not to happy with. I might drop it. But hell do I feel like I need a teacher.

Swagatram.