Marks of Attack Speed, Defence on Seals and Glyphs, Quintessence of Lifesteal => Outsustain

On laning phase, U have to outsustain, outfarm every single enemy that crosses Ur way. Killing isn't the most important. Harass Ur opponent, always ward River and tribush, but dont chase. U can dive at level 6 if U want, but remember, losing more than 12 cs for a kill makes u lose money.
To farm, just equalize the HP of the melee minions, then spin back to be safe AND finish them.

during Mid Game, When U have Urand Ur boots (at least), U have to take down the tower to make the enemies focus Ur lane.
If enemies are on Ur lane, they can't kill Ur people. Always buy Wards, and push as far as U can. Spin through walls to flee, and if you anticipate well, they will never catch U. When U have taken the second Tower, U will have to roam, call for drake, and support Ur team (By supporting Ur team i mean coming from behind to Kill the other team)
Ur an assassin with a life saving Ultimate. U can Go in, kill them and go out without dying. Just do it. But if Ur team is behind, remember u are bad at defending. Push like hell on every lane u can
that will help Ur team and make u some extra gold

Ur a monster in Late Game. Come from behind, destroy AD and AP carry, then go for the inib. Ur teammates should be able to win 4v3 when the 3 ones dont have any damage. Or kill the 5, but never overestimate Ur power. its better to win 8/2/8 than to lose 17/12/0. (8/2/8 is better than 17/12/0 even if u win)