grout for small glass tiles
As just stated, you grout the tiles the same way whether they're 1x1's or 12x12's. To get even grout lines you want to, "strike" the joints after the grout has set for 10 minutes or so. You would use a wood dowel. In this case 1/4" one will work. You start from top to bottom and side to side and run the dowel in the grout lines. It compacts the grout and cleans up the line at the same time. After you're done, clean up the droppings and then wipe off the face grout with a damp sponge. A wet sponge will compromise the grout. After you've cleaned off all the grout the first time, you'll do it again. Clean water and a rinsed sponge, Wipe about 3 feet, turn over the sponge and do 3 more feet. Rinse the sponge and repeat the procedure over all the tile. You'll notice there's still a slight haze. Now take the dry terry cloth and wipe the tiles again. The dust will fall to the floor. The tiles are now about 95% clean. The last bit can be cleaned the next day or you can just clean it the next time you clean the bath. Let the tile set at least 24 hours before using it.
When you apply the grout, do it on a 45 degree angle to the grout lines or you'll pull the grout out of the joints.