Just cut a piece of 1x2" board about 12" long. Cut an "L" shape on the end that will ride over the thicker tile, which you put up first. Scoop in some thinset into the "band" area with a margin trowel and "adjust" or screed it with the board. Let it dry. NOW, you have a slightly raised area upon which to tile the glass and it will be the same height as the field tile.

I absolutely agree with cpccarolyn. Since you can't see into the future in terms of what will look dated, and what won't -- (or if it's dated, will it then be considered "classic" or "trendy"?) you should use the colors or sizes or textures that you like. Regarding resale, in our neighborhood, every house that gets bought gets completely redone anyhow, so who knows?

Oldbat2be, I love your taste in tile...both your stunning backsplash, and also the photo you posted above with the botanical focal tiles. As we consider our kitchen update, I keep coming back to the idea that the area over the range is an opportunity to let some of our personality through. I realize the pitfalls of going too far toward "personal tastes" for resale, and/or looking outdated down the road, but then I remind myself, removing a tile mosaic or medallion is not exactly a horrific job, if a future owner isn't in love with it. (And you know, the whole "life is short" thing.) My kitchen has a low ceiling so I'm hesitant to do any backsplash design except a fairly monotone treatment, under the cabinets...most any kind of horizontal line of contrasting color might emphasize the horizontal, instead of the vertical. So the area over the range keeps appealing to me as the best possible focal area. I don't have experience with using travertine stone over a range, and I'm thinking the cleaning might be an issue. I'm leaning toward some kind of decorative mosaic design using smooth tiles, and I've wondered about using the epoxy grout I've read about here (supposedly pretty bulletproof as far as staining and cleaning, although more expensive.)

Is it the cobalt blue? I had initially picked that, but decided to go with grey and white, and moved the cobalt to my second bathroom remodel. It has a combo tub/shower, and I'm picturing the walls/ceiling in the cobalt blue arabesque/lantern tiles. I'm envisioning it with one of the mission style oak vanities, as I think that will go nicely. I haven't decided if I'm full-on embracing the them and going with a brick-y floor - that's the next project! (you and I seem to have similar thoughts - definitely post anything you find, I love looking at things!)