Start out by choosing the Maniac Class when you create your Mafia Wars character. This will allow your Mafia Wars character to gain energy faster which will allow you to complete more missions each time you log into Mafia Wars.
Each time you level up in Mafia Wars you will gain skill points. Use these points to increase your character’s total energy. This will also allow you to complete more missions each time you log into Mafia Wars. The more points you put into your Mafia Wars Character’s energy, the more missions you will be able to complete each day.
Master all of the job tiers in New York on Mafia Wars. This may take some time to do but once you master all of the job tiers in New York on Mafia Wars, you will receive a Golden Throne. This item will give you 2x energy regain. So you will gain 2 times as much energy each time your energy ticks in Mafia Wars. This will double the amount of missions that you will be able to complete each day while playing Mafia Wars.
Build your Mafia and fight other Mafias. The more people you have in your Mafia, the stronger you will be and the more Mafias you will be able to defeat in fights. Fighting in Mafia Wars will give you a small amount of experience and will help you level up faster in Mafia Wars.