From the first, corners are excreted, well, there are 3 or 4 rows, a pyramid. Corners are the most prototype stage in the masonry, they should be strictly level and the same in height-can use the hydraulicarian. That it turns out 1 row on the corner there will be 7 shells, 2 row 5, etc., Further, when the corners are exhibited, the thread is pulled 1 row from the corner to the corner and masonry lays along the thread. The ligation in a checkerboard pattern is shown in the photo. If during laying it occurs that the joint falls on the joint, in such cases you can stick a half or 1/3 of the shell