If you're looking for a step by step method, you're not going to find it here. I like to entertain myself with my writing. There is a lot written on this topic. If you want books on plotting, they're out there...along with books on just about every aspect of writing.
My method is to start with something in mind, but nothing concrete. At the moment, I'm working on chapter 62 of Sexton Sand. In this chapter, Andy, John, and Tom are carrying King Rajahd'een down a street in the capital of Crescens. They just finished a fight with a bunch of guys, but don't know if there are more people around who would kill them (cheerfully) and proceed with their day.
Fact is... I don't know what's going to happen next. I won't know until I finish the chapter. Given my style, I can tell you the chapter will probably be about 1,500 words long and that it will end with a mini cliffhanger. Then I'll move on to something else happening.
I think the next chapter will be about Benecala in the Fortress Balfour, looking at the thing the druids want so badly to retrieve.
Fact is... I don't know what will happen with that either.
I'll find out the way the reader (hopefully you, by the way) will find out: one word at a time.