Your question is quite broad. There is no one size fits all key that works for everyone. So my response has to be a little broad, but I think I can give you some tools that will help you figure your body out. I work full time with guys and gals, helping with situations just like yours. So here is what i would do. Lets say you started out using a standard 12-16 sets, in the 8-12 rep range for every body part, training everything 1x wk. This is pretty standard, so I figure lets start here. The first thing I would want to do is evaluate your progress. Look to see how much you have grown in this time and of course, look at your diet. You can have the best training plan for your body, but without the nutritional support, it would have little effect on your physique. So from there, if your nutrition is off, we would want to change that first. Then I would look to see what body parts have responded to your training and what has not responded. I would continue to do what is working. If you have body parts that have responded well, I might just continue with what is working. Then if something isn't working, I would like to see some video of your training for that body part. I'd like to see if you are using the target muscle to the max and if there is anything you can do with form to better target the muscle. 9 out of 10 times, this is the answer. Most people are throwing the weight around and not focusing on, for instance the quads, during the squat. They are using the glutes and hams and hips, making the work easier. This happens all the time because guys think they need to be liftin at least X amount of weight. I've taken guys on to my team that were squatting 3 plates for reps, but had little quad size and poor sweep. Then we have gone all the way back to basics, using body weight movements to retrain form. Then over a couple months, work up to 175-225 lbs, but they learned to work harder, get more sore and make better progress with less weight. The key is learning to make the weight hard!! 
So number 1, look at form. As long as you are hitting every body part about 1 time a wk, for about 16 sets, this is the place I would start. See what you can do to work smarter and gains will come. Don't be afraid to use less weight. I know monsters that are killing themselves with 25 lb DB curls. You don't need to use dangerous weight to get big. This is the first steps. There is so much more that I could say, but this is a continuing conversation. It never ends so I have to stop somewhere haha. 

If you want to hire me to work on a 12 wk program, we can build a diet and work on your training. Check my rates out at the Next Level Nutrition page, here at Naps.