Some writers are perpetual outliners. Some write by the seats of their pants. Some are meticulous in their planning. And some just wing it.
I'm kind of somewhere in the middle. I hate planning every move but I also hate shooting in the dark.
To me, the process of plotting is like a road trip. Some people have every details planned out. Some people just take off and drive. I'm kind of in the middle of the road, so to speak:
I usually have a general idea of the plot and story arc. (It's a cross-country trip, starting from New York to Los Angeles, following a southern route instead of northern)
I then set up the the "set pieces" (or major plot points) and write them down -- sort of an outline but really rough and only the set pieces, which are more like guideposts or destination stops. (I want to make at least four different stops: St. Louis, Santa Fe, Phoenix, and Las Vegas)
Then I just write and see where it takes me. Sometimes the whole thing deviates from my original idea and takes on a life of its own, which is always exciting but also nerve-racking: where the heck it's taking me? But I never lose sight of the story and where it is going so I'm not completely lost or running in circles. (Just drive... if I make a detour and end up in Denver, cool. See what happens. But I always make sure I'm going in the right direction so I won't end up in Vancouver or running in circles near Miami)
My best plot comes when I put my characters in situations where they have to make tough choices. When they make the "unpopular" or "unexpected" choices, that's when the plot takes on a whole different direction and it becomes exhilarating to write and read. (the best experiences are always the unexpected side trips or detours... off the beaten paths).