If you are like me, then you can quite possibly be a little of both. Some writers like to follow strict guidelines. They will map out their entire novel with a structured outline, sometimes ending up with outlines a hundred pages long. This works very well... if you're that type of person, if you like to know what's going to happen before it actually does.
A completely fictitious example of an outline that I just free-styled for your entertainment and educational purposes:
I. Amelia is born in a small village where the people all have blue hair.
- A. Amelia is born with pink hair
- B. Amelia can make flowers grow with her singing voice and the other village girls are jealous
- C. Amelia is kidnapped by a group of girls as a joke, and locked in a hidden cage.
II. Amelia is rescued by a foreign magician who happens to walk by and hear her singing
- A. The magician wins Amelia over with his excellent dancing skills
- B.The magician let's Amelia work for him and showcase her magical skills
- C. The magician falls in love with her
- D. They get married and find that with the combination of their powers, they can create the greatest, most magical singer/danger the villages had ever seen.
- d. Amelia gives birth to their little treasure, Gaga.
III. Gaga changes the world
That was just a brief showcase of what you can do with an outline. It can feel a bit restrictive for some, while it can relieve some of the pressure for others.
I enjoy the surprises you find when you refrain from using an outline. Although sometimes, I use a mixture of both methods. I usually start at the beginning and let the characters guide the story. Whenever I feel as though the writing has become a little lack luster, or feels forced, then I may do a brainstorm, jot list, or a simple outline to keep me focused. However, I find that whenever I try to follow an outline, the plot always takes an unexpected turn. Of course I don't want to stifle that creativity by forcing it to follow a predetermined path. Sometimes, you just have to let the words flow.
Remember, there is no wrong way or right way. This is purely a question of preference, and I believe you must try both methods and see what gold it yields for you.