We hired a designer to put our ideas on paper and she figured out all of the calculations for us as far as the material we needed. Originally she said we needed 120 square feet of tile. We looked around until we found some close out tile that we liked. We bought all they had just in case we broke any or the calcs were off a little. It turned out we deeded 150 feet of tile. Since it was a close out tile we had to either buy all new tile, find something that closely matched it and hope nobody noticed, or get a second style of tile that complements the first tile. The first tiles we bought were a grayish 6 inch tile and we finally found some much darker grayish/black mosaic tiles that complemented them well. We only used the mosaics in the spa and spillover area to keep a consistent look though.
We went with a stamped concrete for our decking and it did not look good with our tile at all but we pressed on with the build anyways. One thing we realized was that the decking needs to match your landscaping and the waterline tile needs to match your plaster, pebble, quartz or waterever you use for the bottom of your pool. There is a very distinct separation between the decking and the actual pool and that is fine. Check out my picture and you will see what I mean.
In your pool I would keep the waterline tile consistent even though the materials around it changed.
In the picture below I absolutely hated how the decking didn't match the tile.

Then after installing the plaster and filling with water I realized that it looks great. The tile and plaster match, and the decking matches the landscaping.
