You want a little detail, you want something a little different, but you don't want to pay an arm and a leg for fancy mosaic tiles? I hear ya. Then this is a great tub base design idea for you.
Choose as your main tile a tile that has a matching 2x2 or 1x1 tile. Seems obvious right? I say this because for many of the new large porcelaine tiles matching small tiles aren't offered. Believe me it can be a real pain to find another tile with the same color tone. This is especially true when it comes to beige tiles, good luck finding one that matches, it's crazy hard!
Trim the top edge with a row of the small tile and then tile the deck in this tile as well. I think this is a great, simple design. You could even add a few more rows of the small tile if you want. I'd measure the height of the tub base, calculate how many whole tiles of my main tile fit without having to do any cuts and then the remainder do in the small tiles (btw, usually an odd number of rows looks best). Nice simple design idea and less painful on your wallet too.
Oh and if you do fall in love with a large tile that doesn't have a matching small tile, here's an option - get a marble 1x1 or 2x2 tile. The drawback is that you will have to seal it every few years, the advantage is that surprisingly the stone 2x2 & 1x1 tiles are often cheaper then the porcelain tiles of the same size. They are also prettier too. Oh and make sure to check that the thickness of the small tile is the same as the large tile.
images via: home interior design