How can I get the best out of my workout (lifting weights)?

I usually workout at least 3 times a week. First, I do bench press, 2 sets more than 10 reps of 90 lbs, 105, and 115. After that I do curls using the bar, 5 sets, and usually 10 repetitions. After, I do incline bench press using dumbbells and decline using barbells. I'm not really happy of what I'm seeing right now. There's an improvement but I want to achieve my maximum when I lift weights. Also, I usually do the same things when I go workout. So are there any tips from you guys out there? Should I do pyramids, drop sets, what kinds of workouts with free weights should I try? I'm 15 year old btw, 150 pounds and 5'7". Thanks.