I trail ride my RM125 on a daily basis. I found keeping your revs up/using the clutch is something you will begin to do naturally as you begin to feel the difference between what your machine can and needs a little help doing.
I felt a little improvements in the mild port polish process.
I felt big improvements in my low end torque with boysen power reeds and the much disputed ICatGBsixt device.
I also use a iridium spark plug
the key to low end power in my case is using the wasted air fuel mixture naturally expelled by my exhaust pipe via achieving a more complete,and efficient burn.
just my experience