The Exercise Book

As the title said, this is going to be an exercise book, for me to try new styles and generally improve my own style too, I'm also taking this time to improve on spelling and grammar, so I apologise if I make mistakes.
I'll be doing a mix of echo exercises and playing with my own ideas and concepts, I ask that you guy's recommend books and authors to look into and do some exercises based around them. or even send me a couple of prompts if you think they are interesting enough.