I've been trying to explain a simple way to understanding crochet filet. It took me awhile to get it down and with the help of this pattern you will too.
Any worsted weight yarn
Size G or F crochet hook
Crochet Filet equation: Inside each empty block are two stitches depending on them being filled using two double crochets as well as using a double crochet in between each block.
19 block X 3 stitches per block + 5 Chains for each end =62 stitches you need to chain to start.
Step 1: Ch 62 st
Step 2:DC into 8st from ch
Step 3:Ch 2 times then skip two stitches and DC into next stitch until end forming 19 blocks.
Step 4:Ch 5 times on top of the last 19th block then skip two stitches and DC into next stitch. Do this until you have three rows of boxes.
Step 5: Make 8 DC box
Step 6: DC 2 times into three boxes as well as in between.
Step7: Follow chart below on when to fill in boxes and when to not.