A lot of younger guys in my gym often ask: what do you do for your quads? How do you get your legs to grow?

The not so simple answer is to get "uncomfortable" when you train them.

We often start our weight lifting journey doing bench presses and bicep curls. The squat rack is often invisible or something we hang our sweatshirt on. When starting, I was guilty of the same. Leg workouts were nonexistent. Besides, who is going to see them anyway?

What I mean by "uncomfortable" is to push yourself past the ten rep limit. A limit that we often count as the best number of reps for each set.

I'm referring to a strategy called strip sets. I was reducing the weight and keeping the same set going. Most avid gym people know what I'm referring to, but not to the point of getting uncomfortable.

I spent continuous training sessions on the hack squat machine, and after multiple warm-up sets, with 4-5 45 lb plates on each side to achieve a max sets of 6 -8 reps 3 -4 sets complete. On my last set, I would start having someone assist me by stripping a plate off each side and completing six reps. repeated until a single 45 lb plate was on either side and repping for 20 -25 reps.

Side note: You can do this strategy on the leg press machine on alternate days as the hack squat workout. In other words, pick one exercise that you will do, the strip set system for that workout. Don't do multiple strip sets on the same day on different machines starting.
Give that a try for a month in your leg workouts and see if you get the "uncomfortable" feeling that I had mentioned earlier.