Need slab help!!!

I need help finding big crappie! every time I go out on big water I have this problem. I can catch a mess of dinks, but im tired of that. what do tournament anglers do differently to catch slab crappie? do big fish relate to different structure? do they have different feeding habits, are they even in the same area as the small ones??? im guessing years of experience helps too. but I need some tips. iv only fished perry a few times but I want to start fishing it alot more b/c its the closest crappie lake to me.( so any tips for perry would be appreciated.) :dono