These are sketches live and untouched on cheapo photocopy paper. I like photocopy paper because it has a lot of tooth on it and it really works well with ball point pen. I also use the cheapo ball point pens because they bleed less and seam to have a better feel. The more expensive ball pens tend to lay down too much of that oil based ink and thus the lines smear. The sketches below are done on one letter sized piece of paper.
The side view small car sketch below is a play with not knowing which way is front or back.