ponlo named the best items for “fours” in the early game

You can even buy two Sage’s Masks if the game is very fast-paced: use one later to upgrade to an Urn of Shadows. Arcane Boots are terrible. But you can buy them after your first core item if your team really needs them.

You can pick up a Ring of Regen in your starting buy or early in the lane. That way, you won’t have to spend too much gold on health regeneration, and it helps you get boots by the 5th or 6th minute for your first night ganks. This is just my theory—I might be wrong about the reasoning.

The Essence Distiller must be either on you or on the team, unless the opponent has a lineup like this: Ember Spirit, Witch Doctor, Dark Willow, Dawnbreaker, and Terrorblade.

If you realize they plan to group up around the 15–25-minute mark and engage in nonstop team fights, and there’s no hero in the back that the Essence Distiller can help “isolate” so your mid laner can jump on them, then I think you should consider more useful items. For example, Blink Dagger, Aghanim’s Shard, Eul’s Scepter of Divinity, or Glimmer Cape.

Sentry Wards are very powerful. Just watch a couple of Saksa’s games, and you’ll see just how much wards influence the way he plays the map. He constantly monitors the map, creates safe zones for himself and his team, and can venture into dark areas to place Observer Wards because he knows he won’t be seen. Some players also focus heavily on blocking enemy camps: this hinders the opponent’s support’s movement across the map if they have to travel far just to unblock a camp. Essentially, you’re making the first move, so your opponent is constantly forced to react. Another point: a likely countermeasure is to always keep at least one Sentry Ward on you so you can immediately unblock the nearest camp if it’s been blocked.

Carrying an Observer Ward with you is a very powerful tactic. I’ve lost count of how many times I’ve played against a top-tier support who simply carries an Observer Ward with them while moving across the entire map. This puts constant pressure on me: I have to keep track of their movements to figure out where I can take it down.