Basic BeretNote: This pattern should be worked in the round, but if worked on 2 needles just add 1 stitch to every stitch count, and leave a long enough tail to sew the flattest seam that you can.
Supplies: Yarn and needles to knit to the gauge of about 4 stitches to the inch. This should be about a standard worsted-weight yarn on size 7 or 8 needles [USA]. You should be able to knit any size hat with about 4 ounces of yarn. You will need needles in size 7 or 8, and size 3 or 4.
The band: Measure the intended wearer's head. Subtract 1 inch and multiply the result by 4. For example, if the head is 21 inches, subtract 1 for 20 inches, multiply by 4, for a result of 80 stitches. Cast-on that number of stitches on the smaller needles in a very simple stretchy cast-on, or Kitchener's cast-on if you know it. Work in k1-p1 rib for about 2 inches.
The body: Switching to larger needles increase every other stitch for 1 row. I recommend using the m1 increase, which is done by knitting in the stitch in the row below, then knitting the stitch. This will result in multiplying the stitches on the needles by 1.5. An 80 stitch cast-on will result in a 120 stitch crown. This will produce a beret with a crown slightly less than 10 inches across.] Knit in stocking-stitch for about 3.5 inches, which should be about 22 rows.
The crown: Decrease 8 stitches every other row until 8-15 stitches remain. Whether or not you line up the decreases is optional. If you line them up it will make a pinwheel design on the crown. Cut the yarn leaving a small tail, run it through the remaining stitches and pull firmly tight. Fasten securely and weave in the end.
If you wish to have a bigger beret, then knit even for about two inches after the increase row, then increase a stitch in every 3rd stitch. If the cast-on was 80 stitches you will now have 160 stitches on the needles. This will result in a beret about 13 inches across. Knit even in stockinette stitch until the work measures about 6.5 inches from the original increase row. This should total about 40 rows. Continue from that point with the crown as for the smaller beret.
When done wet the beret and let dry thoroughly blocked to desired size and shape. If you can make a plastic form in a round the size of the finished beret and insert it inside while drying that would be best.