The cluster stitch can be created with a varying number of stitches in the cluster. Follow the instructions for the number of stitches used in your pattern. For this version yo, insert hook in st, yo, pull through st, yo, pull through 2 lps on hook, [yo, insert hook in same st, yo, pull through st, yo, pull through 2 lps on hook] twice, yo, pull through all 4 lps on hook, ch 1.
Cluster Stitch