To earn money from writing you have to master the language you use to write in as well as possible, and it is good to know other languages as well, to enrich your vocabulary. For this you need vocabularies, dictionaries, grammars and expression guides. It’s not as hard as it seems.
Educational writings
You can earn money by writing various educational writings or tutorials. For this you need to be as organized as possible in writing and structure the material as well as possible. Writings like this bring a lot of money to those who deal with it. For this you need to know the subject very well, what you want to teach others.
Literary writings
In order to earn from short stories, you have to give free rein to your imagination on paper or laptop, create characters, give information through what you write that can be useful to those who read you. When I say information, I mean how a character acts or behaves, what they do and why. So the reader of the short story will learn or be inspired by what you wrote to solve a problem in real life.
Copywriting
Copywriting is written advertising. It is the way to get a buyer to buy a product by means of words that convince them that that product is what they need or must have. Copywriting is currently the highest paying job for writers. Copywriting is the most profitable, but it is also the hardest.
Poetry
You can convey, express or evoke feelings in writing through poetry. People don’t just feed themselves with food and they don’t just need warmth and other necessities of life. People, humanity, has fed and still feeds on feelings or experiences. It is an addiction specific to all people.