Something I've recently started doing during my weights sessions at the gym is to move my foot or hand position for each set. This has revealed that small adjustments to position can affect the demands on the muscles.
For example, on the horizontal leg press I've been putting my feet high, middle or low on the vertical axis — one set of each. Now I also position my feet wide, middle or narrow on the horizontal axis. Each position affects my muscles slightly differently.
That's got to build better muscles over time …