Which shrubs, guest?

I'd echo that response but add that maybe you've chosen shrubs that aren't particularly bushy anyway - or you've not been feeding and watering and the soil is poor, it depends on the plants.

Or maybe the shrubs need the leaders to be cut out???

Who knows, impossible to answer properly Guest as we don't know which shrubs you are referring to. Join GoY, it is free and we don't bite, and ask again telling us which shrubs you are referring to.