Mad Men Sketches

It's been a while since I sat down and had a little sketching session. Here's my attempt at drawing two characters from one of my favourite tv shows, Mad Men. I'm always happy with the last thing I drew, and I always feel whatever I've done before is never as good. But when I finished these drawings I realized how constrained my sketch work is. Why do I put so much restriction into my sketches when my finished art works (Akumu Ink designs) are so scratchy and loose? Hmm...Something I feel I need to explore more. It's very strange that as soon as I draw in my sketchbook I feel like I need to prove to myself that I can seriously draw. Hope you guys like these, and if any of you artists have suggestions feel free to crit to help me out.