What I used:
- 2ft by 4ft plywood board. Home depot had a lot of boards to choose from. Mine cost about $5
- 8 faux redwood tiles, 12" by 12". These are sold individually, are $1 per tile and have a sticky back.
These were the only individual 'wood' sticky back tiles they had but Home depot has a ton of flooring to choose from. Vinyl tiles that look like stone to nice real hardwood looking planks you can piece together. Pricing varies and the nicer the 'wood' the more expensive it gets.
That's all you need.
Once you peel off the paper backing of the tile it's ready to stick to your board. I did 2 rows of 4. There's a small border at the front and to the right of the board because it's not exactly 2ft by 4ft. But it's not noticeable in photos.
Voila. Hardwood floor.