As for me, I'm not too fussy. I like silence, although the man outside pressure washing his driveway and car does not seem to know this. I like a cup of tea, and that is just in the process of brewing, despite the 35 degree Celsius heat. Other than that, I don't need much else. Other than a desk that is.
Somebody just asked me what my writing space looks like. Here it is. It's a bit messy, it has a bowl of half eaten Special K, a wonderful book about symbolism, and a whole host of other stuff that could be tidied away, including that idle computer that runs at a speed inconsistent with life. This also functions as the reception desk of our medical office! Multitasking in practice.
What does your writing space look like? What can you not write without?