Lay your area rug flat on the floor and put heavy objects at the four corners of the rug. This will encourage the rug to remain flat instead of curling back up. Leave the objects on the rug for 24 hours.
Measure your rug to find length and width and subtract 1 inch from each measurement. If the rug is meant for a hardwood floor, cut a piece of rug grip, which is available at home supply stores, using the measurements you collected. Rug grip is made from a textured rubber that doesn't move, even on slick or wet floors. The rubberlike texture keeps the rug in place and also protects the floor from the material underneath the rug.
Place the rug grip on the floor in the area that you want the area rug. Lay the area rug over the rug grip and reposition as needed until you are satisfied with its placement. Walk back and forth over the rug to test for any movement of the rug or rug grip. It may be necessary to use doubled-sided carpet tape if you noticed any movement.
Cut pieces of double-sided carpet tape according to the measurements you took earlier. Turn the rug grip over and place the doubled sided tape at the four corners before laying it back on the floor, tape side down. Position carefully and press down against the rug grip to secure it to the floor.
Add tape to the top of the rug grip at the four corners and down the center. Lay the rug on top of the rug grip and reposition it as needed until it's straight. Walk all over the rug to secure the rug to the tape.