If you are playing as a red team and feel the need in the warding the enemy jungle this guide will definitely help you. But do not look too much at the color of the team, the Summoner's Rift is mirrored map, so just flip the image in your head, and use this guide!
Blue Jungle: Best Wards
The best possible option is to put wards at each entrance to the Jungle on the blue side, it will give you the most important data that could be used to predict the movement of enemies. This data (location of enemy jungler) will be used by your team as a signal to retreat or to meet the enemy while he is not expecting a counter-gank.
The Bottom side of the Jungle is one of the easiest to ward, Support will always have a spare minute to go here and place some deep wards, that will secure his ADC or Mid Laner. At the next image, you will see three separate places for Control Wards or various Trinkets:
The top jungle is much harder to ward, after all, the Support is pretty far from it and just could not afford to waste so much time, leaving his ADC unprotected. So in most situations, this part of the map will be without the proper vision control. There are a lot of warding locations, but there are not really good warding places for a Control Ward that could turn the game or something like this. Most of the Control Wards will be destroyed almost instantly, but still, they could gift you some interesting and valuable piece of data.
There is one simple rule you need to understand, while you are playing the League of Legends. You will never have a full vision over the enemy territory but if you will have an approximate understanding of the enemy's position you could always plan your Macro plays with ease. So you do not need to have a full set of wards across the jungle, just highlight the entrance positions and you will have enough intel to plan your further actions. Just increase your map awareness and teach yourself to always keep one eye at the map. This is a major part of the basics of Macro gaming, but without a macro, you will not be able to climb to the high enough Elo Leagues.
Sometimes you will be forced to ward your own jungle, especially if you are falling behind from enemies or just not meet aggressive enemies who are insanely good in the invading and ganking. In this case, you would love to see wards near every entrance to the Jungle and some vision over the river. That visual control will give you enough information and react time to decide the best solution in your uneasy situation. If you are farming a wave of minions and seeing that enemy Jungler is entering the jungle on your side, then you could think about two possible outcomes.
First of them is simple - you just retreat, saving your life, but forcing you to get back from the precious sources of gold and exp, in the face of minions or jungle monsters. This is not always the best choice, but if you are feeling that the enemy is in his prime (spike of power) then it is a reasonable choice. With practice, you will learn more about the league of legends and will gain an ability to correctly evaluate your own strength and your chances in skirmishes with the enemies. Clear knowledge of the match-ups are required to successfully use the second possible outcome, but if you are not as experienced as Boosteria players (check them out at the official website https://boosteria.org) better use the fall-back option.
But if you are pretty sure in your strengths or have a Support on your side then you could perform a counter-gank attempt. If it will succeed you will gain an enormous boost in experience and gold (especially if you will be able to make a killing blow). To make this happen you need to awesomely feel your own champion, your ally and correctly evaluate the chances of surviving in the struggle. Of course, it would be not bad at all if you will be able to kill him and die afterward, but we are wanting to enhance our skill up to perfection, isn't it?