Mix the grout according to the manufacturer's instructions. It should be the consistency of thick oatmeal before it is applied. If you accidentally add to much water simply let it sit for a few minutes and it will thicken up, or you can add more grout. Stir until smooth. If mixing your own colour be sure to mix enough grout to cover the mosaic to ensure colour consistency. Allow the mix to stand for 10 minutes, re-stir and then the grout onto the tiles.
We suggest that you use gloves when working with grout, while it is non-toxic it can dry out your hands. You will go through a few pairs whilst grouting. Apply the grout in a diagonal motion, ensuring that the grout goes into the entire depth of the joint. Sculpt it on your edges to make a nice smooth edge, remove the excess grout with a your gloved hands or sponge. Keep a container of water next to you to wash off the sponge as you go.
Once you have covered your entire piece and filled in all of the spaces, wipe off as much of the excess grout as you can with your gloves or hands. After you do this allow the piece to sit for 20-30 minutes or until the grout becomes hazy. Then take a slightly damp sponge or cloth and wipe off the haze. Buff and shine the tiles with a dry cloth. Remove as much grout as you can from the tile surface, as it will be much harder to remove later. Do not use paper towels as they flake off and stick in your grout.