Are you focusing on driving off the floor with your heels and squeezing your glutes when squatting/pressing? Makes a huge difference in activating the quads.
Take the quads through its entire range of motion, a press/squat with feet pointing out, a press/squat with feet pointing neutral, a lunge, extensions so your biomchanically lengthening and shortening the quads. (full stretch / full contraction exercises are different ranges of motion for a muscle)
Add in CNS techniques like a rack lockout high pin squat, training to failure...etc...etc...