Train your weakest body parts twice per week and you might just make them that tiny bit bigger!
My delts have always been a lagging body part and after consistently hitting them 2X per week they are starting to develop, even though I'm on a cutting diet... I try to hit them from every single angle possible and pause at the top of most isolation movements, such as side raises, for a good 2-3 seconds to really engage my delts and feel that deep burn.