How to poke as vayne?

I carried myself all the way from bronze 5 to silver 5, so i decided to play a ranked game in silver 5 thinking it would be as easy as bronze 1 was. I played vayne and died maybe 4 or 5 times in lane. I didn't really care, because thats what always happened in my vayne games. Id die a few times in lane, then mid to late game i would three shot everything and end up going something like 22 8 17. I found out that Silver 5 is a bit more different than bronze because people actually know how to push and end before late game. The enemy team got three inhibitors between 20 to 30 minutes. Then they got baron and pushed for a sure victory. Recently, ive been playing more aggressive than before because I saw Gosu do so on his stream and still win lane.I used to play back and farm, taking long sword and three health pots to sustain the poke while csing. Now, I poke and start dorans blade and one potion. I end up dying a lot more in lane. How does gosu pull this off without dying? Why don't people poke him as much when he is csing? In bronze people do the all mid thing and teamfight like 5 times per game. In silver 5 no one did that, they would stick two or three at mid and the other two at bot. We would have to constantly run around to save our bot and mid turrets.