How many hours a day are you not writing? Frankly, the answer should be none. Most writing is done far away from the desk as you soak up the minutiae of everyday life. Whatever you’re doing, wherever you are, your senses should be primed, eager to interpret the sights, sounds and smells around you. That sky isn’t just blue – it’s watery or silvered or glassy; dragonflies don’t just fly – they dart or hawk or skim; nothing smells just nice.
Get into the habit of really seeing things, observing tiny detail, the nuance of all you encounter, as if you were a child seeing it for the first time. The veins in a leaf, the actual hue and texture of blood, the taste of fresh coffee. Don't write about your memory of these things - which will be laden with clichés - go and experience them first hand. (Except the blood; wait for that to come to you.)
Writers don’t stumble blindly through life; everything and anything should fascinate you. Especially people. Describe their behaviour in your mind; assume their motives; listen to them, watch them, study them. What gives them away? Where does that nervous twitch come from? Imagine what their worst fear might be, the terror they’ll never speak of? Who was their first love fifty years ago? What events have shaped them? What thought sends them to sleep each night? What's the one thing they'll never tell anybody?
There are no days off, I’m afraid. You are always writing.