My main client gives me hardly any instructions, just keywords and which website it is for, and I'm supposed to figure it all out for myself. But it turns out that she's mostly fine with whatever I write, as long as it's over 500 words, on topic, got the keyword in a few times, and free from errors. So these articles are usually really easy to churn out.
My other regular client is the opposite. The articles are longer, with more specific requirements, but she gives me much more guidance. She provides sources and even tells me how to structure the article. My next one for her is 1500 words about WordPress plugins for $60, which I can easily get done on Monday. I have also done some proofreading and editing work for her, just because she is not a native English speaker. In fact, that was the first type of work I did for her, and then she started getting me to write her articles for her as well.
Grammarly can be a bit troublesome. I've had problems getting it to work with Google Docs. So, what I now do is copy and paste from Google Docs into the Grammarly site. It's a bit of extra faff, but I don't mind too much. I can whiz through Grammarly in a few minutes and I'm done.