How to crochet a cluster stitch: one shared top

Build the shared top

1. Yarn over, insert in the stitch and pull up a loop. Yarn over and draw through 2 loops. Leave the final pull-through unfinished.
2. Repeat that partial double crochet twice more in the same stitch. You now have 4 loops: the original active loop plus one for each partial stitch.
3. Yarn over and draw through all 4 loops. One cluster top remains.

Use spaces without gaining width

Start with 6 single crochets. Chain 2 and turn; do not count the starting chains. Repeat [cluster in next stitch, chain 1, skip next stitch] twice, then work a cluster in the next stitch and a double crochet in the last stitch. This practice row has 3 clusters, 2 chain spaces and an edge double crochet, so it ends on a stitch.

For the return row, chain 1 and turn. Single crochet once in the edge double crochet, once in every chain space and once in every cluster top: 6 stitches. Mark the first return stitch, which is in the edge double crochet.

Read the special-stitch definition

A cluster made across separate stitches decreases the count. A group made in one stitch does not consume those neighboring stitches. Confirm the insertion points before following a cluster abbreviation.

If your hook has only 3 loops before closing, one partial stitch is missing. If the group looks like a shell, you may have completed every double crochet instead of retaining its last loop.