Okay! Here goes the pattern for my slip stitch hat. I use slip stitch in the round, in the front loop only for the bulk of the hat. It is not as quick as some other stitches, but I love the fabric it produces - smooth, solid and lightweight. Another result of this stitch is that it curls up on itself, creating the rolled brim, therefore you need to create a bit more length to make up for the curl.

less than 220 yards, 201.2 meters, worsted weight yarn - I used Knitpicks bare peruvian highland wool that I dyed with plants

If you are adventurous, you can adapt this for a different sized yarn, my only guideline would be that you use a hook that is larger than what you would normally use for your yarn.

K hook - 6.5mm
H hook - 5mm

stitch marker, or piece of yarn of a contrasting color, or whatever you want to use to keep track of rounds

any size your heart desires!

not really an issue but mine worked up to be 20 sl st flo per 4" , 10cm, and 20 rounds per 4", 10 cm in the portion worked with the H hook.

I suggest loosening up your gauge when using slip stitch because the tight stitches are difficult to get the hook into. Also, might I suggest using a hook with a pointy head if you have one.

stitches:

slip stitch - sl st - Insert hook into indicated stitch. Yarn-over and draw up a loop through both the stitch and the
loop on your hook. Slip stitch is complete

magic ring - http://www.planetjune.com/blog/tutorials/magic-ring-right-handed/

slip stitch front loop only sl st flo - make a slip stitch through the front loop only of the next stitch

slip stitch increase - sl st inc - make a slip stitch in the back loop of the next stitch and then a slip stitch in the front loop of that same stitch

This pattern is done in continuous rounds with no joining. Use a stitch marker or a piece of yarn in a contrasting color to keep track of your rounds.

with worsted weight yarn and a K hook

Start with a magic ring
1 - make 5 sc in magic ring - 5sc
2 - make 1 sl st inc in each sc - 10 sl st
3 - make 1 sl st inc in each sl st - 20 sl st
4 - make 1 sl st flo in each sl st - 20 sl st
alternate rounds 3 and 4 until you have a disk that is pretty flat (it is okay if it is a little ruffly) and large enough to cover the diameter of your head. I did two more increase rounds ending up with 80 stitches around.

change to H hook and continue round 4 until hat is desired height.

I added five stripes of blue for interest. Two rounds blue, two rounds grey ... it seemed to make the slip stitching go faster :0)

I added a chain stitch flower at the top to make it more girly, otherwise this could be a good men's hat, too.

I suggest steam blocking your hat to make it look and feel it's best.