GRID PATTERN* 
Grid sectioning, despite being the pattern shown on one of the more popular dreadlock sites on the web, is generally speaking NOT the best choice. Although this method does allow for easy maintenance, the aesthetic result of this pattern is usually very undesirable. With each row and column stacked like a grid, the dreadlocks also end up stacked in this manner which means there are typically a lot of ‘gaps’ and ‘bald spots’ between columns of dreadlocks that are considered unsightly by many.
As mentioned above, the only case in which a person might purposefully want to choose this sectioning pattern is if they are looking to get SUPER tiny locks (typically in ethic hair) that they are wanting to be able to braid and/or twist into intricate styles.
This sectioning is completed one row at a time by first carving off a single row starting at the nape of the neck. (Check out the page about section sizing how to determine what section size to choose.) Ideally in this method, and the next, you want each section to be equally wide as it is tall to keep it as aesthetically appealing and functional as possible. Then, once the bottom row is sectioned you do the same for the next row up making sure the rows are as parallel as possible and the sections are stacked on top of one another in a grid-like pattern in neat rows and columns. Continue this process with each row.
Once you reach the crown of the head (this spans from the row that finished at the top of the temple and upwards to cover the entire top of the head), the section of hair remaining to be sectioned into smaller sections is generally ovular and you will want to carve your rows now from side to side (ear-to-ear) and continue to stack the sections similarly to how you did it on the rest of the head.
See photo at top left for an example of this sectioning and the subsequent ‘bald spot’ that resulted. (*Denotes a pattern that is NOT recommended!)