The basic rule of leveling is to be near creeps when they are being killed. The hero gains experience from every killed enemy creep/hero in 1000 range of his position. The laning phase, as it’s called, comprises of the necessity for heroes to be ruling their respective through experience and gold advantage. The consists of last hitting, for more gold and experience, and denying the allied creeps with the hotkey A, for denying enemies major amounts of gold and experience.
This video shows how far you can stay behind to gain experience
Pulling Creeps
This is my gang, they help me getting ahead
As a lane progresses in its war for dominance, the closer a team can get the opponent to their side of the lane the more power they have over the creeps. One effective method for achieving such a goal is creep pulling. The concept is to allow a creep wave to approach your tower from the base but then to grab neutral creeps nearest to the lane and bring them out to fight the lane creeps. The lane creeps will follow the neutral creeps to fight, which in turn will allow you to last hit the neutrals and gain experience/gold. In the process, your enemy's creeps have to move close to your tower for more free creep kills, while they get no gold whatsoever, ultimately reaching the goal of lane dominance. More on this will be covered in the Creep Pulling section of this guide.
Choosing the Hero Lineup
I have Charizard, Pikachu, Squirtle and Bulbasaur!
If you want an early experience lead, you can chose to pick a hero designed for creeping neutrals from the beginning:
Tempest
War Beast
Legionnaire
Ophelia
Swiftblade (with Bottle - advanced)
If you decide to do it like that, you would want a hero with good survivability on the easy lane (bottom Legion, top Hellbourne.) So even though he's solo against two opponents, he will maintain experience meanwhile having a mate farming neutrals. In the end, both heroes of the bottom lane will have an experience advantage if not a gold advantage. The hardest part is the fact that the solo hero must stay alive and orchestrate ganks with the jungling hero.
Tempest is one of the best heroes for farming neutral creeps from the start.
Advantages of Solo Laning
I'm not good with people
Such laning will mostly only occur in the middle lane, if no junglers (heroes who kill neutrals from the beginning of the game) are integrated into the team. As the middle lane hero, you have the responsibility to control the two rune spots on opposite ends of the river and gank the lanes that need assistance. You will have quite an experience advantage and gain a quick ultimate which comes in very handy for ganking. Certain things matter more in solo lanes than in other lanes with a partner. You must know when to leave and when not to. While in double hero lanes a hero can leave to get a rune or gank out, the other can control the lane. In a solo lane, you must be sure to push your lane enough that you can go a rune or gank quickly enough without the opponent hero pushing the tower and eating your lane. If you push it and keep them busy, you also won't be giving them as much experience when their tower is taking last hits constantly.
Soulstealer - one of the best soloing heroes in the game.
Importance of Leveling
I .. need .. more .. POWER
Over the various heroes of this game, leveling ahead of others is more pertaining to some heroes, while other heroes should not worry as much about it. When you have support heroes such as Demented Shaman and Accursed, it’s important to pull creeps so your carry can gain more experience in the lane while you are away. Leveling is not nearly as important for you, as it is for your carry. A hero like Demented Shaman is great for a team because he does not require as many items or levels to be effective support. Don't get this wrong though. Never should you just stay away from your lane and end up level 1 for the entire game.
Other heroes that semi-carry and carry the team require experience much more than others. A hero like Soulstealer or Wretched Hag thrives for more experience than others because their skills scale very well as the game progresses into mid and late game. Out-leveling your opponent makes it much easier to compete against them.
Now, lets say you have a team like this:
Wretched Hag
Corrupted Disciple
Blacksmith
Pyromancer
Magmus
There's a problem. Two of your heroes require the experience gain of a solo lane: Wretched Hag and Corrupted Disciple. So what should you do? One way to fix this problem is to let Corrupted Disciple solo mid, Wretched Hag solo bottom/top, and have Blacksmith, Pyromancer, and Magmus go into top/bottom to run what is called a Tri-Lane. Having those three heroes in one lane can create havoc for the carry/babysitter that you face. Blacksmith flaming hammer reduces magic armor while Pyromancer and Magmus can easily nuke one down. Killing the heroes and extreme harassment keeps those three heroes the same level as the two heroes they face. Overall, your team will benefit in levels and money, while the opposing team will crumble to the Tri-Lane (if played right).