Grow room ideas

Hi all,
I have a new room to grow in its a caller/basement.
It's quite a small area 120cm x 41cm it's a tad damp looking, dose anybody have any ideas (all welcome) on what I should cover the walls with cheap as pos, I can use the space more then using a "grow tent" thanks everyone

Mylar (Emergency Blankets rom camping section) or Panda Film. Or Reflectix if you want something insulating.

Cheapest way to go and effective is what the dude above said, mylar blanket. Their like a dollar or 2 for each and reflect pretty good. Ive used them for my grow op a few years ago and worked out great. Just make sure you get it flat as possible for maximum reflecrion.
Or if possible white paint works great too