The easiest way to work with any filet pattern is to use a graph. Very few filet patterns are actually written out as you will see from the examples below, it takes a great deal of space to write out one row of a graph.
Filet crochet is a series of boxes worked in double crochet.
Filled in boxes create the design while open boxes form the background. You adjust the size of your pattern by using different combinations of dc and chains for each box. By working as little as 2 stitches per box or you can increase that from 3 to as many as 5 stitches per box you can change the size of your finished piece. The easiest filet is worked with 2 stitches for each box. To begin your pattern, count your blocks and multiply that number by the number of stitches used for each block.