If you feel like the tank is getting crowded and overgrown, do a big slash and burn... Leave the choicest leaves, and rip out the rest. Get some new plants and try your hand at them. If you're new, don't try to resign yourself to one particular tank layout... Find what you like, and run with it. If you know that you can grow plants well (which is pretty obvious judging by the pics), then look into developing an aquascape instead of just a cluster of plants. If you like a tightly packed tank, look at dutch scaping... If you dig on pristine natural scenes, look into Takashi Amano's Nature Aquariums (ADA). Your plants having large leaves is not by any means a problem, but a marker that you're doing something right.