If its at home, can you get more resistance into your exercises??, dips and pushups are fine but you really need to get some weights involved.
Shoulders are side/front raises/back rows - overhead press with some resistance/weight, and chest press/fly's with weight for the front to build size...
Plenty on the net to check but increase in weights slowly, good rest and eat right. Change your routine every so often and be consistant, I saw my best increase with deadlifts and overhead press routine so keeping it simple might be an idea if you can get the equipment..
Hope that helps.