13 sts and 10 rows = 4-1/4 inches square
Please check your gauge for garments and hats. There's no need to do all that work to find out it doesn't fit.
I am a loose-stitch crocheter. I know this because of something called gauge. Change the hook to fit the gauge.
How to crochet the gauge - First try the size H hook
Row 1: Hdc in 3rd ch from the hook and in each stitch across (13-sts)
Row 2: Ch 1, turn, hdc in each st across
Row 3 through 10: Repeat round 2.
If the sample square does not fit CLOSELY to 4-1/4 inches by 4-1/4 inches, then you need to change your hook size. If the sample square is smaller, then increase the hook size to an "I" size hook. If the sample square size is larger, then decrease the hook size to a "G" size hook.
When you get your gauge correct move onto the next step, making the cuff.
Whichever hat you choose to do embellishments for, I use a G-size hook to crochet many of the embellishments. Depending on your gauge will depend on the hook size for the embellishments. Use the NEXT SIZE down from the hook you determined to use from the gauge swatch above.