KrystalClear_xox
For me I just read some mafia stories on wattpad, they really give you inspo for story ideas. Also discuss it with other people, or keep track of any ideas you have, no matter how big or small. No one really knows what mafias are like in real life, so I guess their stories about them are just what they think of mafias, and your story should be what you think of them too. I hope this helps!