Focus heavily on getting stacks on your Q. As soon as you hit 770g. go back and buy tear of the goddess and 1 hp and mana pot. if you ever want to harrass, hit them with AA. sometimes you can throw a q at them and that can do decent dmg. if youre jungle is ready to gank, you initiate with your stun. when placing stun, dont place on them... place it in front of them. make sure you follow up immediately with meteor and baleful. when facing an assassin with gap closers (yasuo, akali, katarina, etc), hang back and just q minions and q them as well to keep hp down so that they dont get reckless and dive you.

position yourself in the back so that your tanks can go in first. when placing down stun, get as many as possible and NEVER FOCUS TANK. All of your skills should be focused on adc or mid, depending who is stronger and more of a threat. sometimes, if you are at a stalemate, you can put yourself at the front so that you can place stun and initiate a fight, but dont get caught. NEVER INITIATE A FIGHT IF YOUR TEAM CANT HANDLE IT!!!! if you do get caught in a team fight, remember that you have zhonya's and sereph's embrace... USE THEM!!