Arterra LLP Landscape Architects Thanks! What a compliment. The tile on the fountain was a custom blend of tile from Heath Tile. I know they don't may the chartreuse color anymore, but here is a link to their site to see what they have for colors. We also blended sizes. I did a mock up of the layout, to be sure it was all pretty evenly spaced and we didn't end up with strips or masses. The tile guy loved me....
http://www.heathceramics.com/home/pages/tile-build

Arterra LLP Landscape Architects These were poured in place, because they matched the larger slab where the table is. It is possible to purchase these premade and have them brought in. Typically they are still custom made by a concrete fabricator.

Sarah Clayton Thank-you! Beautiful project!

Summerset Gardens/Joe Weuste I plant garden paths in many of my projects. It's a terrific look & really helps to soften the space. These type of plantings require very good drainage & a good soil mix. Unfortunately these type of plantings do require maintenance. They can grow over the stepping stones so they need to be trimmed back every now & then & of course weeding. It's the price you pay for this look. I've attached a sample planting.
Gravel is another solution....many to choose from however as stated in some of the above comments this too has pros & cons.

SRM Architecture and Interiors Here's an example of mixing mulch, pavers & gravel in an outdoor design. It's a different project than your space, but we thought it might give you an idea about how you can mix these materials. Good luck!