We recently had hardwood flooring installed in our house. The first problem that I encountered afterward was that our couch needs to sit away from the wall, but on the hardwood, it always slid backwards. I wanted a solution to keep the couch exactly where I wanted it but also one that wouldn't show too much. Ultimately we decided to use pieces of the leftover hardwood cut to the length I needed. Here's what we did:
Measured the distance that I wanted to keep the couch out from the wall, then cut two length of flooring to the right length.
I purchased a sheet of sticky-backed felt (like the felt feet) at the hardware store and cut 4 strips, the length and height of the board ends, to protect the wall and the couch legs. I stuck those to the board ends.
Then I took some non-slip shelf liner and cut to strips just smaller than the board so they wouldn't show.
I put the boards behind the couch, with the liner underneath, and pushed the couch back against them. The couch has stayed in place, just how I want it and the boards just blend in with the flooring!