What next?
It’s that feeling after an impulse buy of a beautiful ball of yarn because it is SO soft, and SO pretty, but it’s only a single ball.
It happened to me with a ball of Katia Concept Cotton Merino, which is an Aran weight yarn with 115 yds (105 m) per ball. Luckily, as my colour choices are ahem shall we say consistent I had a bit of Fyberspates Cumulus left over from another project, in almost the same colour. Held together with the Katia, and knitted on US 9 (5.5 mm) needles, the result is a comfortable slightly slouchy everyday hat, in super-duper soft yarn, and it uses almost exactly the whole ball of Katia.
It starts with a provisional cast on, and you work the main part of the hat before coming back to finish the ribbing, so that you can use up all the yarn, and not have to play yarn chicken.
One size: suits average female head.

SUPPLIES
One ball of Katia Concept Cotton Merino or other Aran weight yarn with at least the same yardage/metreage.
115 yds (105 m) of Fyberspates Cumulus or laceweight mohair with similar yardage/metreage.
A US 9 (5.50 mm) (or size to obtain gauge) circular needle. A 16” (40 cm) circular is recommended. Dpns (optional) for the crown shaping.
A US 7 (4.5mm) needle (or 2 sizes smaller than your main needle) for the ribbing.
A sewing up needle.
Waste yarn and crochet hook (optional for crochet cast on).
4 stitch markers.