A nice brush with natural bristles and a blue-dipped wooden handle measuring 17cm in length.  Really good for removing tile splinters and biscuit crumbs from your working area.  It may sound trivial, but it is very easy unthinkingly to use the side of your hand to sweep away crumbs of glass or smalti, with painful results.  This will do a much better job and save your hands at the same time.