Hello r/leagueoflegends! I already posted this on r/summonerschool, so if you see it there, it's the same.
So a long time ago, back in season 3 or 4, I saw RF Legendary do a trick were he put a ward over the thick wall in top lane when he was blue side in lane. It was useful as you could check for ganks, or push up without showing that you already warded the bush. This trick was lost after the changes to the Summoners Rift map and I have yet to find any place where they talk about this. I have found the new trick that is needed in order to place the ward over the wall correctly almost 100% of the time.
I recommend doing all the steps with a locked or centered screen.
Line yourself with the crack in the wall by clicking in the inner most part of it. Click it multiple times in order to ensure that you are as close to the wall as possible.
Aim your cursor with the little brand/leaf part of the pine tree that is to your right. Make sure your cursor placement is on exactly the tip of the point otherwise it will not work.
Step 3: Place your ward, it should place near the inner part of the bush but it will still give you full vision inside the bush and limited vision outside the bush.
It does look a little buggy, but I have dummies to show that even the lower part and the out part of the bush are still in range.
Some might be asking, "How about larger champs like tanks?", and for you my friends, I have also tested that and it has been shown to also work.
I hope this post has been helpful and enjoy the free wins.