Comfort Conundrum
You'd think if you're too comfortable, it wouldn't be a stimulus to writing but in my opinion, it's just the opposite. Only about 3 square metres are required for carving out a 'welcoming' writing area.You've got to love going there.
Make it colourful but not overstimulating. Have a small table on which to rest your tea and crumpet (or whatever your nibbles and beverage of choice) for break time. If you crave silence, then having a music station nearby isn't mandatory, but good lighting is ---preferably natural (like a painter) but overhead and behind the shoulder, at least 60 watt recommended. Best chair style? A comfortable 'high', arm chair e.g. wing chair, club chair etc---for leaning back, head supported, and meditating; perhaps an ottoman to elevate the leg. Best If your writing corner is located by a window to look out of ---for those mini-breaks (trance-like day dreams that come and go) when your brain is in creative thinking mode. Just make sure the area is relatively uncluttered -- distracting otherwise.
Tip: It helps to have 2 such chairs, and a Biewer Terrier sleeping on the opposite one when you're working. Company is also a comfort :)