So this shifts ever so often. Is the current warding habit to ward towards the river or towards the wall? I've been yelled at for both. Ward near the river you get more vision but it can be found faster, ward near the wall you get less vision but they have to go further into the bush to find your ward.
Vision Wards in bushes are intended to maintain vision of an enemy going in there. If it's not necessary for combat purposes, you can place the ward further out to gain better coverage. Control Wards will almost always go in a bush because it's too easy to kill them otherwise, though in some cases you'll place them outside of a bush to clear enemy Vision Wards when Oracle's Lens isn't appropriate/available.
In other words, it's a case-by-case basis. Sometimes the optimal placement cannot be done due to safety reasons (no vision of some enemies that may be nearby); weigh the risks of putting your wards in the best spots, and if there's a decent chance you'll get caught putting it there, opt for a less optimal spot or ask for an escort.
