Flooring Tile - new wall tile - grout "depth"...standard or preference ?

Something came-up as I just reviewed my tiling of our new bathroom....
what happened is that we used a border using fancy glass mosaic tile turned 90 degrees for a diamond-accent effect. Then half-cut standard 4.25" tile was placed between the turned glass sections...to finish out the border which was about 6 inches wide.
Bottomline: the gaps in these border tile were considerable...partially because the glass mosaic was 4 separate pieces already meshed/masked together....and the masked pieces had a large gap already (1/8 - 3/16").

So interestingly, I finished the remaining wall tile and grouted a lot so that the borders on the tile were closer to the width of the grout lines on the border.
Now I wonder if I should have used 1/16" spacers in the remaining wall tile that would have eliminated the need to grout almost to the surface of the tile to get a wider grout line ? Anybody with me on this ?

Since then, I've reviewed many commercial installations of tile (Schools, etc), and noticed the grout lines are quite "shallow". With my "deep grout" technique, you get a pretty attractive contrast with the colored tile (and I have been complimented on it), but the look is "flat" as the rounded edges of the tile no longer show.

Did I make a huge beginners mistake here or is this a preference issue ?

Just a preference thing, but you need at least 2/3rds of the joint filled with grout, I would guess.:)

but do you think that since I had to match the wider grout line of the decorative border tiles, I should have spaced the tiles a bit using 1/16" spacers ?
Using spacers means more work though..... :(
I would say that I filled the tile gap almost 80-85% in most cases....such that the grout was almost at the tile surface.