First of all, you should consider the thickness of construction

The thickness of the mosaic itself has difference, from 2mm to 5 millimeters, which is various. Even some Mosaic with special material can reach a centimeter. In addition, the thickness of the and ceramic tile also have difference, so in order to make the metope level off in whole, sometimes in order to consider the leveling layer, it is necessary for you in the thinner area.

Secondly, the joint spacing of construction should be uniform

The seam spacing between the block Mosaic must be uniform, and the size should be equal to the one of the original small block Mosaic, so that the whole metope could be integrated, but a large Mosaic.

Thirdly, control the construction rhythm well

In the process of tiling Mosaic, it is possible to find the phenomenon, like flow slurry, the whole piece slide, and so on. Those situations are generally caused by the poor construction rhythm. The better method is to the next till the previous cement is slightly curing, then the effect would be ideal.

Fourthly, jointing with the tile grout 
Nowadays, it is generally use the tile grout for jointing. Use the wet white cement to wipe again; and let the dry cement make it solidification; finally, use the dry towel to scrub and clean as soon as possible, so that the effect which is made by theMosaic wall is more uniform, the adornment effect is better than the piece of material, for that you can't see construction joint.