How do you stop furniture from sliding on harwood floors?ie: sectional

They sell rubber pads for under carpet. If you cut small pieces of this and place them under the feet of your furniture, it should help a great deal. Otherwise, they make square hard rubber (senior moment) things for under the feet of furniture. Should be able to buy them at Home Depot or Lower.

Cassi Morehouse-Pierce Buy the rug backing for no slip and glue the rubber to the legs of the furniture.

If your sectional has turned legs try this:

https://smile.amazon.com/Shepherd-Hardware-Round-Rubber-Furniture/dp/B013IS4AEC/ref=sr_1_5?ie=UTF8&qid=1499693421&sr=8-5&keywords=furniture+leg+cups

If it has larger flat feet then I agree on the no-slip carpet pad. You can get this same material at the dollar store, sold as shelf liner.