Once you've built a strong base of strength (that should always come first in the gym) add some size-focused rep ranges and specialized hypertrophy exercises.
Reps for Size
To maximize muscle growth you need to leverage classic bodybuilding rep schemes. The sweet spot for reps is 8-12. That's heavy enough to create significant tension in the muscle, yet light enough to allow multiple reps and metabolic stress – another key component of muscle growth.
Another effective strategy is high-rep sets of 12-20 or more reps. Though this has been called a "muscular endurance" rep range, these high-rep sets can create one hell of a muscle-building challenge, especially with isolation exercises and challenge-based finishers.
Techniques for Size
These are isolation exercises, but now that you've built your strength base you can perform them with weights not covered in pink vinyl.
Just pause at the hardest point, or mid-rep, and hold the weight there for 15-30 seconds. This works great with a barbell curl. If you find yourself struggling to hold the weight for this long at the beginning of the exercise, decrease the weight. After holding, go immediately into 8-12 reps without resting. Pre-set holds will improve your mind-muscle connection and accelerate muscle growth.
This is a great way to get a good pump and build muscle on the heels of your strength training. In fact, one recent study found that when you perform an exercise to failure with loads of 30% of your 1 rep max (very light, 20+ reps) it's nearly as effective as using loads of 80% of your 1 rep max. So when you train isolated muscle groups, do the exercise until you can't do it any longer. You'll get the pump of your life.