Okay, now we're ready to level. Just remember, you must level every single time off of your energy bar if you want to do this fast. For the first few levels, it's no problem leveling off of your energy bar. You just master the jobs one at a time and you'll level up each time without a problem. This brings us to a second key point- you must strive to master every job. Every time you master a job, you get one stat point. This will give us more max energy and make it easier to level off of the same energy bar. Almost every job in the first tier, street thug, has a 1 energy: 1 exp ratio. This makes it tougher to level. By level 6 or so, you will be struggling to level each time off of this poor ratio. At this point, it is time to start attacking.
Find a Whipping Boy
Now, for the first 200 levels, your character will have no attack. Therefore, it is important to find someone really weak to attack! It is also a good idea to have around 10 or so people in your mafia at this point. If you need people, just go to mafia wars fan page on facebook and add a few people as facebook friends from the "add me" threads. Make sure you buy a couple weapons and pieces of armor for a few people in your mafia. That way, you'll win most of your fights vs people with small mafias. There appears to be no downside to attacking both a low level person and a person with a small mafia. So, the best course of action here is to find a person you can consistently beat, then bookmark them so you can always come back and beat them! I attacked the same level 40 player from level 40 on, without any problems. If you are a high level player, you will even get high level drops of low level players. So just find someone you can easily beat and bookmark their info. To do so, you must right click on the link to their name, then click copy link location, then add that link to bookmarks. Pic example: