Writing
It tastes like slightly-too-cold beverages left on a desk for too long, like coffee that probably shouldn't be drunk, but it's the only thing nearby, so..
It smells like a slightly stuffy room, like the old coffee, and the random snacks grabbed when somebody comments on how long it's been since you actually stopped
It feels like slightly-cramped fingers or hands, the twinge as hands are stretched, shaken, before picking up the pencil again, or settling over the keyboard again
It sounds like many things - the muffled scratch of papers, the click of rapid typing, curses, slightly-maniac laughter, muttering, shifting, quite exclamations.
It looks different, depending on who is the focus. Prim, pen in hand at a modern desk, or slumped over a couch, buried in blankets, or scribbled on notes during a busy day. But no matter what it looks like, it has the potential to be a life-changing gift to those who are lucky enough to read the results.