League of Legends (LoL) Question: The Most Important Aspects of Jungling?

For a jungler, your early game is they key to the rest of the game. If you have a bad early game, it is almost impossible to recover. Most guides on this site for junglers show the early clear. That is because this is the most important thing you will do all game. A good clear early will give you the levels you need to gank a lane and will give you the gold income. Efficient clears are also important. Learn the timers on different camps so that you know when to clear them. This will make sure you have the gold income to buy items. Knowing when and how to tax lanes will also help with this. Keep track of the summoner spell cooldowns for your lane enemies too. This will make your ganks much better and more reliable. If an enemy is low health and under tower, you may be tempted to dive, but if you know they have heal and flash both up, you will know better. Know when the best times are to go for objectives and learn how to contest the objectives. This depends on a number of factors, including how good you are on the champ you are playing, how good the enemy jungler is, and where your laners are with respect to the objective. Finally, you are the main person responsible for vision on the map. Make sure you are buying control wards and placing wards in both your and the enemy jungle. This will give your team knowledge of the enemy team's movements and camps, allowing them to counterjungle and avoid enemy ganks.
Does this all seem like a lot? That's because it is. Many people don't appreciate that a jungler has a ton of responsibility in a game. It can be argued that a jungler alone can win or lose a game. For this reason, losing a lane is often blamed on a jungler and losing objectives is often also blamed on you, even though the majority of your objective control is based off the picks the laners surrounding it can get and how well they can push the enemy laner around.
IF YOU TAKE ONE THING FROM THIS, AND ONE THING ONLY, DO NOT BE A BABYSITTER. Your job is to help the even lanes get ahead and ahead lanes get aheader (yes I know but it made me laugh), not to pull dead lanes back from the grave. If you have a midlaner that is 0/5 with half an item and the enemy midlaner has two full items, do not gank for them, no matter how hard they flame you for not doing it. If you gank this lane alone, unless you are way ahead, you will most likely die, further feeding that lane and losing any lead you may have had. That lane is lost and there is nothing you can do at that time. Your only hope is to tandem gank with your bot or top lane. A good lane to gank for is a top laner that has been trading kills with his enemy. He isn't ahead, but he isn't behind. That usually means the matchup is even. Use this to your advantage, as a gank there will most likely win your team that lane.
If you are panicing right now you can stop. If you were to master all these aspects, you would be a challenger tier jungler. Play to your strengths and hone your skills one aspect at a time. What I did was play a series of games focusing on a single aspect of jungling until it was second nature. Once I had it down I did the same with another. I started jungling by learning how to farm and did nothing else all game. My team was mad, but that is what you have to do to learn the position. Use the practice tool too, as you can refresh your health, mana, and cooldowns at will. This can also help you learn your champ's mechanics. Unlike any of the lanes, a jungler can't just play 5 games and be a master. While I am not saying laning requires no skill, it is no where near as mechanically intensive as jungling (I have played all roles and am speaking to my personal experience). Learn the trade, and practice a ton. Do not get tilted because in the beginning you will fail much more than you succeed. When you do learn it however, enjoy taking credit for every lose and getting no credit for your victory. A jungler's life is a lonely one. Good luck in the Rift :).

Since you may not want to read another huge answer, I'm just gonna say efficieny. Clearing and pathing more efficiently than the enemy jungler will result in an XP lead and being able to get to fights faster. I've been working on this and since my main, evelyn, is great at farming anyways it means I can get ahead in farm pretty easily

Your opening (where you start) and what you do for the next few minutes is really important right now.

Good early game skirmishers (Xin, Pantheon, Graves, Udyr) will look to control scuttle crabs assuming you have lane priority and your chosen jungle champion beats their jungle champion.

So commonly if your are a good early ganker like Xin Zhao you probably will start Red, level 2 gank Mid, soak enough XP from Mid to hit level 3 and go take the nearest Rift Scuttler if your are still reasonably healthy and then run across Mid lane and take the other Rift Scuttler.

Alternatively if you can't get a gank in Mid then you can go Red, opposite side of the map Rift Scuttler, and then invade the enemy jungler at their Red buff.

If you lose the 1 v 1 vs the enemy jungler then you need to play it a little safer, Red > Opposite Scuttle, and then head back into your jungle for Gromp > Blue > Wolves (or something like that) > Base.

Get good enough with your champion that you don't have to watch yourself doing the camp and use that time to pan around the map with your your camera or the F2-F5 keys so you can see what is going on in the lanes and then path to places where you think you can get ganks or so you can notice when people blow summoner spells (because your laner probably will not tell you).

Don't force ganks. If their laner is healthy and has a big minion wave to their advantage then your job is only to make sure your laner doesn't get turret dove if their jungler happens to be on that side of the map.

Learn to layer your CC. If your laner has point and click CC then they go first. Then you follow-up.

Try to come in at an angle such that you don't have to use your gap closer or Flash until after they use their escape abilities and then use your gap closer to follow.

Remember that ganks don't always have to result in kills. If you chunk the laner so they have to stay so far off the wave that they can't get gold or maybe even XP then your gank was good. If you get their Flash/ Ghost that is also helpful to your laner. Try to come back within 5 minutes (for Flash), but if you can't you can't. Sometimes there are more important places to be on the map.

Keep your farm up as best you can. Good times to farm are during down time. If your ult is on cool down or one or more of your teammates is in base, those are good times to farm. But don't get so caught up in doing camps that you are late to a party, especially if you are playing a good skirmisher like Xin or Graves.

Be vocal and call for objectives. Don't get lost in chasing people around the map. Get a pick, or win a skirmish/teamfight then get your team to take an objective.

People are commonly *******s to their jungler so mute if people start to get on your nerves.