Bruised but good

So I finally was able to return to the gym after my elbow injury. It's black, blue, purple and green, but it feels good. I done lite curls, bench, butterflies, and worked abs, and my elbow didn't bother me. It's still sore, but as far as it hurting, it doesn't. I guess ice, tylenol extra strenght, and a heating pad really work. My chest is really sore, because I haven't worked out in over a week. I've tried lately to really work on my strength. I not just a strong person, but I've never really worked on my strenght. I've always been the one who does more reps. lately I've done like 5 set of 6 reps of heavier weight. Does anyone know a better way to build strength? If you have any suggestion, let me know. Thanks.