Space between you and your opponent is your enemy. Space creates an opportunity for him to gain an advantage such as getting you off his back.
Leg riding without pressure is useless. If you get a figure 4 between one leg and his hip you need to SQUEEZE. This takes practice but not applying pressure is useless. Pressure during leg riding will keep him from moving as much or get him to make a mistake because he is uncomfortable. Pressure will cause his low back to ache and fatigue which makes more opportunity for you.
If you are leg riding always, always try to control his head/neck. second choice is controlling one arm. I always taught my wrestlers that if you control the opponents hips and neck you will win the battle.
NO SPACE, PRESSURE, ATTACK NECK or ARM.
keep your hips off the mat, don't let your opponent plant anything of yours on the mat