When you get up in lane your goal is to support the lanes not doing as well and force the control of the map in your teams favor. When top lane crushes out 5 kills and forces a b, run down to mid and tell the jungler to meet you and 3v1 their midlaner. He sits under tower? Great, go 5v2 bot lane, grab 2 kills or 2 b's and crush the tower then go back mid and 5v1 that tower sitting scrub.
Get the idea? The goal is to maintain control of the map. If you're truly ahead, abuse the hell out of it like you would against bots. Your jgs behind? But you're up 7 kills? Their Blue buff about to come up? Go gank their jg and steal their blue and gromp to catch your jg up. Mid just died? Run down to keep the tower alive. Dragons up, your sup and adc are low but just forced a b? Grab your tp or boots and run down there to tank it for them.
Global Presence and Map control are how you carry. NOT KDA numbers.