When I was in college, I filled my Berkeley apartment with thrift store furniture, Goodwill dishes, and the requisite futon couch. It was like any student apartment, but there was one creative touch that never failed to wow guests, my painted floorcloths.
I've been making floorcloths for several years now, and nothing makes an apartment look groovier. In one day, you can have the best-dressed floors in the neighborhood, and discover a new creative outlet.

So, pull on your old T-shirt and overalls; we're going to make a floorcloth.

Size matters
Art stores carry both primed and unprimed canvas. I buy primed canvas so I don't have to worry about shrinkage and making a gesso-y mess on the floor of my apartment.

The first step is to decide what size you want your floorcloth. (3' x 5' is a nice size for a medium room.)
Measure and cut the size you want, adding three inches to the length and the width to allow for a one and one half inch hem on each side.
Mark the hem lines with a colored pencil, not a graphite one, which will show through lighter paint colors.
Fold the edges so you know where the lines are, and cut off the corners of the cloth so that when you fold the hems together they meet in at 90-degree angle.
Now, turn the floorcloth upside down and apply rubber cement to each side of each hem. Let the cement dry for a while before you press the edges together.
When you have folded the hems, weigh down the edges with heavy books until dry.
Now turn over your hemmed floorcloth. The fun part begins.

Design time
Maybe you want a border, or a diamond pattern. Measure the geometric design if you decide on one, and mark it with a coloring pencil.

Now paint! Keep the acrylic paint fairly thin with water; you want the finish to be flat, not lumpy. Keep your brushes wet. I have ruined many brushes by allowing acrylic paint to dry on them.

Sponge a darker or lighter color on top of the base color to add texture. Acrylic paint dries fast, so you can start painting the details on top of your background quickly. I use all kinds of motifs: pears and cherries, flowers and leaves, bees and chairs. The sky's the limit.

Don't worry about symmetry and perfection. A floorcloth looks even cooler when it is a little off kilter.

Signed and sealed
When you have finished painting your design, and perhaps signed it in the corner, let the paint dry and prepare to coat with sealer.

Apply an even coat in one direction with a foam brush or a sponge. It will look milky, but it dries to a clear finish. Don't go back over a part you've already done as it begins to dry quickly. This needs to be a quick thick coat.

When the first coat is dry, apply another. And then another. I always apply at least four coats of sealer. When the final coat is dry, put rubber matting underneath and proudly lay the floorcloth in the chosen room.

Voila! Beautiful handmade art that you will have for years.

Clean your floorcloth with warm soapy water when needed. Apply another coat of sealer every couple of years to keep it looking bright. Happy painting.