First, consider the pen you write with. It should be a fast-writing pen because your thoughts are always much faster than your hand. You don't want to slow up your hand even more with a slow pen. A ballpoint pen, a pencil, a felt tip, for sure, are slow. Go to a stationery store and see what feels good to you. Try out different kinds. Don't get too fancy and expensive. I mostly use a cheap Sheaffer fountain pen, about $1.95. It has replaceable cartridges. I've bought hundreds over the years. I've had every color; they often leak, but they are fast. The new roller pens that are out now are fast, too but there's a slight loss of control. You want to be able to feel the connection and texture of the pen on paper.
Think, too, about your notebook. It is important. This is your equipment, like hammer and nails to a carpenter. (Feel fortunate---for very little money you are in business!) Sometimes people buy expensive hardcover journals. They are bulky and heavy, and because they are fancy, you are compelled to write something good. Instead you should feel that you have permission to write the worst junk in the world and it would be okay. Give yourself a lot of space in which to explore writing. A cheap spiral notebook lets you feel that you can fill it quickly and afford another. Also, it is easy to carry. (I often buy notebook-size purses.)
Sometimes, instead of writing in a notebook, you might want to directly type out your thoughts. Writing is physical and is affected by the equipment you use. In typing, your fingers hit keys and the result is block, black letters: a different aspect of yourself may come out. I have found that when I am writing something emotional, I must write it the first time directly with hand on paper. Handwriting is more connected to the movement of the heart. Yet, when I tell stories, I go straight to the typewriter.
Another thing you can try is speaking into a tape recorder and feeling how it is to directly record your voice speaking your thoughts.
Experiment. Even try writing in a big drawing pad. It is true that the inside world creates the outside world, but the outside world and our tools also affect the way we form our thoughts. Try skywriting.
Choose your tools carefully, but not so carefully that you get uptight or spend more time at the stationery store than at your writing table.