To begin work on your Independence, here’s a basic exercise. Practice to play a Steady Quarter note off of your Hihat Foot, then Play corresponding Eight Notes off of your Bass Drum Foot.
When you have this going steady and in time, with your hands now, play a Paradiddle over the Top, maybe on the Snare until everything sounds like one single unit.
Then go ahead and play the right hand part off of another Drum voice, maybe the bell of the Ride Cymbal,keeping your the Left hand still playing on the Snare.
Play and Practice together until it feels like one single unit and then begin to Push and explore by spreading the notes and or the sticking pattern of your chosen Rudiment among various Drum Voices.
Try and see if you can incorporate a heel-toe pattern off of your left foot and off of your hihat into it…
Below is Video illustration