I like to free-motion quilt using the start/stop button and not the foot pedal. I just find it easier to not have to coordinate my hands and feet together... concentrating on the hands only, moving the fabric, does help. I turn the machine down to half-speed when I do that.
I've never been able to get the hang of the knee lifter... maybe because I'm so short. It feels like I have to strain and contort myself to use it!