I used to be a diehard pantser.  I wrote my first book, If I Fix You, without any idea where the story or characters would end up and it took me FOREVER! When something significant needed to be changed I had to re-write half the book. Plus, there’d be days where I wasted so much time just trying to figure out what to write that I’d barely write at all. I was kind of forced into becoming a plotter when I needed to submit a book proposal (synopsis and the first three chapters) to my publisher for what became my sophomore novel, The First to Know. I’d written a synopsis before, but never prior to completing the first draft so this was an entirely new experience for me and it changed everything! I was able to write my entire story in ten pages or so and then when something needed to be changed, it was as simple as rewriting a few pages instead of a few hundred. I was able to work out my story/character issues before I started drafting and I had a roadmap to follow once I did start drafting. No more wasted time! I can write a full book now, start to finish including edits, in six months versus six years! I now write a ten or so page synopsis before I begin drafting. It contains the main storyline but still leaves me with the freedom to develop secondary storylines and characters so I never feel too constrained.