In my story, I have a man that had wanted to become a Death Eater, hiding this secret from all who know him. He ends up being murdered by the Death Eaters for not being able to complete one of the tasks that had been set for him [murdering someone he loved] to test his cowardice and loyalty. I can't remember if I've just read this sequence many times over in fan fiction or not, but how exactly does one go about becoming a Death Eater?

What I remember is them having to perform a few tasks [numbers vary, one to three or so], usually them being something like killing someone and the tasks becoming harder and harder with each murder, ultimately it being someone they love, like a parent or wife/husband. If they end up doing everything that is asked, they become a Death Eater. If not, they are killed or otherwise blamed for another attack and tortured. Is this how it works or is this a common fan fiction occurence? And if it is a common thing used in FF, how exactly do people become a Death Eater?

I don't want them to have the Dark Mark, either, until the tasks are finished and it is official that they actually are said DE. Would this work?