As the others have said, this isn’t a simple question – each fascist regime over the last couple of hundred years has been a little different.
But there are two essential pieces for any fascistic government. The details vary, but two essentials:
1) A powerful leader. Charisma helps, too. The person doesn’t need to be intelligent (Hitler) or strategic or even particularly conniving. The person just needs to be a leader in the sense that he can get people to do what he says. If there is a philosophy (religious or otherwise) it lends legitimacy (or at least rationale) to what he is doing, but that’s not essential. The key point is that there’s a leader who is the focal point.
2) A docile, non-questioning population – this is why Hitler, among others, was so successful. If Germany hadn’t been so worn out from losing WWI and the subsequent depression in Germany, they might have been less docile and less willing to follow Hitler. Same with Italy and Mussolini. And same in a number of states in Africa, although there the issue is not losing WWI or WW2, but being docile because of poverty and low standards of living.
Again, each instance of fascism has its own peculiarities, but the two elements above are essential.