I must say i've been watching a few people play eve and everyone of them has gone wirggles and I always see them do poorly, unless if your going to jungle, theres almost no point in taking wirggles.
your not gonna sit there and auto attack minions to get that creep score cuz you'll get domniated and harassed to hell by the enemy opponent. and the same applies to the lifesteal aspect of it. the only thing its useful for is a ward. but really the amount of money and time you spend just to get a refreshable ward is not worth it.
instead my basic core build is boots -> rylai's -> sheen -> upgrade boots (either mobility or sorc) -> gunblade
that is my core, after that its defensive items and then finish sheen to lichbane
the reason I get rylais as my first major item is because the slow helps a ton. you run in use ravage and since its a multi strike and a single target your applying the 35% slow, twice so it last longer than 1.5 seconds, almost 2 seconds really. This is because your second strike with ravage isnt instant and thus it reapplies the slow. the health on it will help make you a lot more durable giving you better surviability. and the amount of AP on this item will make farming much easier with hate spikes. you can use these things long range and snipe minions for last hits.
the reason why I dont get sheen early is because I dont have much survivability until I get all 3 abilities. without that dark frenzy I aint going to be running away quick enough, and not going to be reliably able to gank well. also the AP from rylai's will help farm much better because I can use hate spikes from a ranged point instead of having to go up and melee the minions where my enemies can harass me.
now you can go for a more AD build, but you will HAVE to and I cant stress it enough, MUST build tanky. you need that defense, the armor and magic resistance cuz you just dont have the burst to kill any champion quick enough before the entire team turns around and nukes you to death. even the ultimate isnt going to save you if you only have base armor and magic resistance, I suggest aiming for at bare minimum of getting 100 of each unless your enemies are lacking one or the other damage type (physical = armor, magical = magic resistance)
hope those slight tips will help you understand the power of eve