Here is a free pattern which is very basic for a

GARTER STITCH BERET
Use any size yarn with a needle size appropriate to the yarn used.(check the yarn label) This hat is knit from the top down in a circular fashion so you will need to use either dpn's, the 2 circular technique or magic loop technique. The hat is also sized in a different manner than most knitter's are used to using.
To make this hat, you will need: Approximately 75 gms of yarn, About 2 yds of scrap yarn (contrast color, smooth yarn) 8 markers, one of which is different for beginning of row. ( I make them out of the scrap yarn) knitting needles appropriate for your yarn and another pair (optional) 2 sizes smaller. A measuring device to measure 5 or 6 inches.
Start by making your markers and row counting device.
Markers—tie scrap yarn around 2 needles with a square knot, leave about an inch tails—make 7
Row counter—use about a foot of yarn and tie the center of it around 2 needles with square knot, flip it over and tie another square knot, another flip, another knot, another flip, another knot. Remove from needles and stretch out. You should have 4 loops, trim these tails to an inch also. The first loop is row 1, the loop with the tails is row 4. Use this for your beginning of row marker. As you knit to it, slip your needle into the loop below the one on the left needle.
CAST ON—8 stitches using circular cast on. The hat is divided into 8 sections. Each of the following direction is reaped 8 times total on each round.
Row 1—kf&b in each stitch--16 stitches total
Row 2—k1, p1, place marker, use a different colored marker for beginning of round
Row 3—knit, sm
Row 4—k1, p1, sm
Row 5—k1, m1, k1, m1, sm
Row 6—k1,p3, sm
Row 7—knit, sm
Row 8—k1, purl to marker, sm
Row 9—k1, m1, knit to marker, m1, sm
Row 10--k1, purl to marker, sm
Row 11—knit, sm
Row 12--k1, purl to marker, sm
Repeat rows 9 to 12 until hat is desired size.
As you are knitting measure from the center to one of the markers. To fit actual head measurements of 16 (18, 20, 22, 24)inches. This measurement shoud be 2.5 (2.75, 3.25, 3.5, 3.75) inches.
When you have the correct size, count the stitches between the markers and remember this number. Continue knitting until diameter of top of hat is 9(10, 10, 11, 12) inches. Complete 3 remaining rows after last increase and work 4 more rows even without increases. You can increase the fullness of the larger sizes by working another 4 rows even if desired. Now begin your decreases.
Decrease row 1—k1, k2tog, knit to 2 stitches before marker, skp, sm
Decrease row 2—k1, purl to marker, sm
Decrease row 3—knit
Decrease row 4--k1, purl to marker, sm
When the number of stitches between markers is the same as it was when you measured for sizing, (that number I told you to remember) switch to needle two sizes smaller and work in garter stitch (knit one row, purl one row) until you have desired number of ridges in band. (usually 3 or 4) , bind off. Work in 2 yarn tails from the beginning and the end and you are finished.

Enjoy,
fran