3 DC Granny Cluster
Starting chain should be a multiple of 3, plus 1.

This granny cluster can be used to create the granny stripe stitch and crochet granny square.
3 DC Shell for Beginners
5-Double Crochet Shell Stitch
Starting chain should be a multiple of 6, plus 1.

Learn more about this stitch here: 5 dc shell stitch
3-Double Crochet Cluster Stitch
This stitch is the 3-Double Crochet Cluster Stitch (abbreviated as 3-dc cl).
Unlike a shell stitch (which spreads out at the top), a cluster stitch gathers at both the bottom and the top, forming a leaf- or eye-shaped texture.

Learn more about this stitch here: 3 dc cluster
How to Single Crochet Two Together (sc2tog)
The single crochet 2 together (sc2tog) is a basic crochet decrease method. It takes two adjacent single crochet stitches and combines them into a single stitch at the top.

Learn more about this stitch here: sc2tog