I think the difference between a king and a dictator is that a king is the top feudal lord and a dictator is the top guy in a nation state.
I think the options for becoming a monarch are:
1) the birth heir of a current hereditary monarch
2) the designated heir of the current monarch (e.g. some Roman emperors were appointed by their predecessor. Although the August didn't call himself "king" because of the historical political animosity to a king, he did intend for the position to be hereditary, but the first few emperors had trouble having sons. Whether the emperors were monarchs is arguably semantic, although Rome was more of an empire [extracting resources from the periphery] than a feudal state, which would argue that they are not monarchs by my definition above. On the other hand, Roman administration of provinces wasn't as strong as a nation-state.)
4) conqueror somewhere and establish a feudal state. It might be necessary for you to have a successful succession in order for history to call you king, though.
I think the options for becoming a monarch are:
1) the birth heir of a current hereditary monarch
2) the designated heir of the current monarch (e.g. some Roman emperors were appointed by their predecessor. Although the August didn't call himself "king" because of the historical political animosity to a king, he did intend for the position to be hereditary, but the first few emperors had trouble having sons. Whether the emperors were monarchs is arguably semantic, although Rome was more of an empire [extracting resources from the periphery] than a feudal state, which would argue that they are not monarchs by my definition above. On the other hand, Roman administration of provinces wasn't as strong as a nation-state.)
3) get elected as monarch [https://en.wikipedia.org/wiki/Elective_monarchy]
4) conqueror somewhere and establish a feudal state. It might be necessary for you to have a successful succession in order for history to call you king, though.