It doesn´t matter if you are a Jungler or not, even as a Laner, it is always important to know the Junglepath of the enemy Jungler. You may ask yourself, but Kingkong why is it so important for me as a Laner to know where the Jungler is. Well if you know the Jungle Path of your enemy Jungler then you will know when to place a ward and where to place that ward.
So first of all, you need to know where the enemy Jungler starts. Either he starts at the botside Jungle or on topside Jungle. In order to know where he starts, you just have to have a closer look on the top lane and the botlane in the beginning of the game. If these Laners get a little bit later on their Lane, it means they have pulled for their Jungler and that tells you where the Jungler started.
However it´s important to know that every Jungler clears the Camps in a different amount of Time. Also the pull depends on the Champions that are pulling for his Jungler. That´s why i will just show you some approximate times when the Jungler will gank your Lane and when you have to place a Ward.
When the Jungler goes for the typical Level 3 Clear, means either Blue Buff, Wolf Camp and Red Buff or Red Buff, Wolf Camp and Blue Buff the Cleartime is almost the same. The only difference here is, if the Botlane does the leash or the Toplane. If the Toplaner leashes for the enemy Jungler, the enemy Jungler will be ready for a Gank at 2:40. That means you as a Laner have to place a ward around that Time. But if the Botlane does the leash for the enemy Jungler, then the enemy Jungler will be ready at 2:30. So make sure to place a ward around that time.
The only difference between Season 7 and Season 8 is, that the Jungler will finish the Level 3 Jungle Path 10 seconds earlier. However if you guys don´t like times and numbers and you are to lazy to pay attention to the in game Time, well i got another Tip for you guys when to ward. All you have to do here is just pay attention to the wave. When the third wave arrives, the so called "CannonMinionwave" then it will be around 2:30, 2:40 and you will know ok the Jungler might gank my Lane now. Drop a ward in the bush and you are good to go.