Clean water in bucket often as to not to contaminate grout with dirty water and loose particles. The grout joints should be of the same consistent shape and depth. After grout has been allowed to harden there will be a haze left by the grout residue that will need to be removed. Remove this residue by wiping over the tile with a piece of cheesecloth until film is removed. Tile and Grout maintenance primarily involves cleaning and sealing the grout to protect against stains.
Tile is extremely durable and requires little on-going maintenance other than cleaning.
A spill, however, that is allowed to sit on a joint for a length of time could leave a permanent discoloration. As long as the spill is cleaned up quickly, grout joints will continue to look new. Sealer is applied with a sponge brush and excess wiped away with a cheesecloth or towel.