Punish buying no Sightstone as Support
As a main support and someone who watches LCS and Worlds I get that the vision game is very important. Season after Season I feel like I understand it better and see more and more how significant it is to win a game.
When I am not assigned to another role and I see my Support playing "Miss Fortune" or even "Pantheon", I often experience that they are not willing to buy "Sightstone" even though laying down and denying vision is one of the most important tasks of a Support. I never won a game with these players. You think the enemy is just magically smarter than you are but then you watch the Supp's items and you realize your Supp rather goes for a "Pickaxe" than for a "Sightstone" and has no intend to play supportive for the team even though that's what the role is for.
There should be penalties for players who do this because it is just plain trolling and there is no reward for the team and the course of the game in not taking "Sightstone". There is no better way for a Support to spend your gold. Everything else narrows your team's chances to win extremly.

and a really aggressive lane is all you need early on the game.
management will give you more than enough wards until mid game. Specially if you have priority.
If they have priority, second tier gold generating items like
and second tier boots like
will give you more utility than vision.
is also an option. Half of the times you scan the area you find no wards anyway (specially on low elo) and you simply carry a