This is the satisfying part of finishing off a tiling job. Once tiles are adhered to the wall or floor surface, the grout fills in the gaps in between the tiles and is necessary to stop them rubbing and cracking.
HOW TO GROUT TILES Photo Gallery
Ready-mixed grouting is a good buy as the consistency is pre-balanced. If you choose to mix up your own, aim for the same consistency as toothpaste. Work on a section at a time and use a grout spreader to work the grout mixture diagonally across the surface of the tiles. As you spread the grout across the surface of the tiles, it will be pushed into the gaps.
When the grout starts to set in the joins, run the flat edge of the spreader across the tiles again to remove the excess. Wet a sponge and squeeze out the excess water. Wipe it across the tiles to clean the area before starting a new section.