Allow Enough Time to Pass
After installing the grout, you want to allow enough set-up time for the grout to solidify and stay in place.
Don't Wait Too Long
You want just enough time for the grout to set, but if you wait too long it will be difficult to remove any grout haze from your surrounding tile.
Allow about 10 minutes for the grout to set. Do not stand on the grout, remember to move across the tiles as you clean, starting at one and working backwards so you don't track back across the flooring. Use a bucket filled with about 1 gallon water and 1/2 cup white vinegar. Dip your rag in the cleaner, wring out and wipe down gently to remove any haze.