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, a pencil, a felt tip, for sure, are slow.  Go to a stationary 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.