Stay upright, try not to lean too much. Use your muscles, not gravity.
Don’t go too fast. Try to make the sled Jerk forward every step. Step, Pull, Step, Pull, Step, Pull.
Use a long strap. If it’s too short you “Pop” and drag the sled forward right into your heel/Achilles tendon.
Dragging forward, with the strap attached to your belt is good for glutes/hip drive.
Dragging backwards is good for thighs. Using some kind of handle in your hands works better than trying to your belt when going backwards.
It is an intense workout. People at my gym always use too much weight and try to pull too fast, and try to go too fast between drags. They get pooped after 2-3 drags. Its more like an “interval workout” than an all out Sprint till death.