Here is the recipe I used to make a hexipuff out of Koigu Kersti Merino Crepe. This yarn is a light worsted weight, more like a DK.
What's a hexipuff? It's a motif used in making The Beekeeper's Quilt. The pattern calls for a fingering weight sock yarn, but I'm using all my scraps - including worsted weight. There are a series of posts on my blog about adjusting the pattern to make hexipuffs of the same size from all different types of yarn. These are modifications - you'll still need to buy a copy of the official pattern to make the quilt.
The modifications are generally to (a) the number of stitches cast on, (b) the total number of stitches the puff reaches at its widest point, and (c) whether there are extra plain knit rows added to the ones specified by the pattern.
This results in a hexipuff that is 3" in diameter (1.5" on each side).
Koigu Kersti Merino Crepe - Modifications
Cast on 9 sts per needle on US Size 3 (3.25mm) needles.
Increase to 19 sts per needle.
Decrease and bind off as usual.
No extra knit rows.