you have to be aware of where your hips are - engage those at start and you'll feel your quads working - keep the tension on them and they grow
too many bad assess do the ego things - load up squats , load up leg press , bust out reps slinging up weight - no feel on the muscles - just hope that someone will notice you and consider you not a failure at life as a man
work the muscle not your ego and you'll have nice legs
GB'er quote " I may not be much to look at but I got strong legs " - yet a pair of medium shorts eats your legs for lunch