Accuracy comes down to firstly not wasting your resources and only secondarily to not missing openings. A flash, an ultimate or 30 seconds wasted during an illusion of opportunity is more costly than going for the safer play - farming until a sure advantage can be gained.
fact: no catchup mechanic makes it imperative not to fall behind in farm early game
fact: not getting level6 before 7:10 without making sure the enemy jungler does the same leaves you open to a buff invade
Eye of the Hawk
Keep your eyes on the minimap at all times and your pinky finger on the Tab button. Make a mental note of all the wards enemy place. Do not be deceived by your knowledge: your enemies know where they lack vision just as well as you do and will generally play defensive around those areas. A gank which can be foiled by enemy using his metaknowledge effectively is not an accurate gank.
Bullseye!
Playing accurately will keep you high in level and gold, making it easier to get bigger gains by seizing opportunities! Haphazard enemies might get more kills and assists, but your actions will lead to more objectives: dragons and towers, more than compensating for their luck. Just like precise knowledge of holds will let a rock climber ascend, so will accurate play help you!