Do as many last hits as you can and farm up really quick.Dont forget to harass enemies with the Q ability.If one of your teammates can get you the blue buff it will be great.Dont use ulti before you have tagged a target with the first ability because then it will go on cooldown and you may not catch up to him later on.But if you are confident that you will kill him you can use ulti without tagging the enemy.But keep in mind that you can still use ulti to jump to an enemy minion and escape.You can also escape by tagging a raid camp and then using ulti top jump on them.Example:If the enemy team is chasing you towards baron and he is spawned you can tagg him and escape if you are not so low...or maybe you can tagg dragon and escape and all the other raid camps..Just be creative with it.But when playing against ranged enemies on mid or somewhere else always stay behind minions and dodge the skill shots..when playing against champions such as : Oriana...Karthus..Syndra.. be sure to use the spheres and absorbe the Damage..or when you have boots and some reflexes it is easy to dodge them.