Like alot of folks are saying, stick to compound movements. Incline Bench for chest, Military Press for shoulders, Dealifts for back, Squats & Stiff Leggs for legs, etc. Going to failure isn't necessary but atleast come close. Try 8 working sets for major body parts, 6 for minor, and 4 for traps and forearms. Over-training is for real. It's an uphill battle as a natural, but, progress can still happen. I've been training for almost 13 years and this year I've put on 7 lbs this year. Now, the last 7 years prior I only put a total of 10 lbs on... So keep trucking.