Here’s what I think a serious writer is not:
1: It’s not someone who scowls all the time and never laughs or smiles and spends all their days never ever understanding even one sarcastic joke.
2: It’s not someone who only writes “serious fiction” or who smokes as they gaze out the window and only writes absolute intellectual wobbly gobbly splendor and spends their evening lounging in artsy cafes while wearing a beret.
Here’s what I think a serious writer is:
It IS someone who has decided that they are a Writer. They ideally want to create a career out of writing, but at the very least they have decided that A Writer is who they are. It will be their lifelong passion. Their life will be dedicated to that art.
I think one of the most important things though is that they show up.
You don’t have to show up to your hobby every day, but you do have to show up to work. It means sitting down in that chair and writing, even on the days when writing is like pulling teeth from a t-rex (meaning, you’ll probably get eaten before you do anything).
And while I would say take your craft seriously, know that what you’re doing is important and serious work (just like rocket science), don’t take yourself too seriously (as with rocket science).
And I would say the biggest thing that make a serious write is this: not waiting around for things to finish themselves and not expecting to all of a sudden become a great writer without. actually. writing.
Really actually, it’s kinda simple.
Just write. Make those stories happen. Make those words into one glorious strand and write till the sun goes down and the lights go up (or maybe write in the morning. Whatever you want to do).