I think it’s valuable for all writers to practice on a sentence level. It’s one thing to be good at plot and character. It’s another thing to write beauty words, beautiful sentences, etc.
My friend Brian has an excellent style website. It’s geared for students in college studying composition but I think it’s fabulous for fiction writers too. Try it and see what you think.
Another thing you can do to help your sentences is to read. And then read some more. And then keep reading. Sometimes you can even find something you love, a book, an author, and then rewrite one of their paragraphs. Maybe even a whole chapter. By doing this, you’ll feel the rhythm of their writing. You’ll start to understand how they construct their phrases, where they put modifiers, why they put modifiers where they put them. You’ll be surprised at what the actual act of rewriting, of copying for the purpose of learning will do for you. Now, beware, I’m not saying you should copy other writers. I’m saying you should STUDY. you should become a student of fiction. You should learn from those you admire, from the masters.
I’ve learned so much from copying down passages from Sylvia Plath, Ernest Hemingway, Sandra Cisneros, Flannery O’ Conner, Cormac McCarthy, and others. So many others.
love and style.