Tension isn’t hugely important. Just use a yarn and recommend needles and you should be okay. This hat can be made smaller, teen sized, by going down a needle size, and child sized by using a 4ply yarn and 3mm needles.

So basically I found a doily I really liked and made it into a hat. Potentially you can do this with any yarn and needles, you knit the doily until it’s big enough for your head, knit down, decrease to an average sized beanie for that size then cast off using a stretchy cast off.

This pattern includes a link to one doily and instructions for how to make it into a hat.

My instructions and project notes can be found here. The doily pattern is published online at this blog, you don’t need to log in and it’s free.

So I just cast on 8 stitches and went for it, although there is a fancy crochet cast on there. I then worked the doily on 9dpns. (yup…) until round 54. You could stop anywhere listed though for a shorter hat. I put the work onto a 3.5mm circular needle and just knitted in stocking stitch for 6cm. If you want a slouchier hat this is where you add the length.
I then knitted one, knitted two together for a round and then did 3-4cm of knit one purl one rib, and finished with 5 rounds of stocking stitch to give it a rolled edge before casting off with a super stretchy cast off. Simple once you’ve done the doily.

You start at the top and increase a lot, before decreasing a small amount down to 120 stitches before doing rib and casting off.