Diamond eyelet (pattern)
This decorative pattern is made up of little squares in diagonal rows that make up a larger square with a star shape inside. It is quite a complex pattern, which is very detailed, but you could try leaving out the central stitch in places to simplify it.
Start by working a diagonal trellis pattern of small squares, each over two threads. Space each line with ten fabric threads. The squares can be worked with four stitches forming each square, or using double length stitches where the squares join each other.
Continue in the opposite direction to produce a diagonal trellis pattern of small squares.
Structure of stitch
Various Authors, The Royal School of Needlework Book of Embroidery (2018) , p.148
Becky Hogg, RSN Essential Stitch Guides: Blackwork (2010) , p.72