The beauty with subway tiles is they are cost effective and they can go modern or classic. The thing is though, they are everywhere but they have been around so long you could never say they are a fad. How do you mix them up?
Use white subway tiles with a dark coloured grout for a graphic and dramatic look. You could incorporate thick black grout or a thinner grey grout. Added bonus, it won't show dirt like a lighter coloured grout.
Try coloured subway tiles for a little less of a classic look.
A modern take on a classic look is to hang them vertically, lay them in a pattern or try a metal tile.
Play around with the materials, colours and grout until you have a look you like.