Feet on floor, although I just moved them from the bottom support beam-type part of the bottom of the chair, whith my chin resting in my left hand (making it very close to the screen and endangering my already-poor eyesight) and my right hand on the mouse.
Oh yeah, and my fingers on my left hand are usually in the “death metal/sign of the beast” position, putting my pinky under my left eye and my index finger on my temple.
Right forearm on desk, elbow at the edge, hand (usually) on the mouse. Usually hold up my head with my left arm, which has it’s elbow rested on the desk, fingertips to my temple. My left leg is crossed under my right knee, my heel against my seat. My right heel is on the leg of my chair, the toe on the floor.
When I take a nap, I put my legs up on my desk, cross my arms, and lean my head forward so my chin is resting on my chest.
My right foot is currently tucked under my left knee. I usually sit like that or I bend my legs and rest my feet on the rollers under the chair. Before I started replying to this thread I was leaning forward so my left elbow is on the edge of the desk and my head resting on my left fisted hand.