Our house had accent stripes when we purchased it. It's all subway tile and then two thin strips of blue/grey glass mosaic tiles. I really like it, I think it breaks up the vast wall of white tile.

I don't have an accent stripe, just a wall of plain white subways. I like them, but understand that they can bore some people. If I'd thought it through more, I think I'd like an accent area of the same color, but different size tiles or liners, so the effect is more textural than color contrast.

I like some of the thin accent strips I've seen, but don't like the thicker ones for the most part. We have a few thin stripes in our hall bath, and to me, they still look pretty after over 3 years. I think that if you have them they are more successful if they are a well thought out design element in the room and not just some stripe of tile stuck in in order to make plain tile "not boring." Plain tile almost always looks OK, but there is plenty of awful looking accent tile out there.

In a tile shower, just use the 2" floor tiles to add an accent, about 2 or 3 pieces tall on the walls, about 2/3 of the way up.

I agree with Linelle. Adding a liner in the same color but in different shapes or sizes breaks up the solid wall of sameness without the "stripe" look some accents can give.

I prefer a simple look too. Using different shapes and sizes if tile in white can make the tile more interesting without bringing in another material or color.

A grout other than pure white will also emphasize the pattern giving it more definition. There are some really lovely showers with simple subways and light grey grout.

Here is a link that might be useful: [White subway herringbone and brick[(https://www.houzz.com/photos/interiors-traditional-bathroom-atlanta-phvw-vp~11718210)

You should take a peak at subway tile panels. No grout - easy maintenance.

http://www.onyxcollection.com/images/accessories/subway-tile-shower02.jpg

Here is a link that might be useful: DIY shower panels