Take a measuring tape and place it around the circumference of the head, slightly above the ears.

Make note the head circumference measurement.

Take the head circumference measurement and make note of that number.  This is your cap length pattern measurement.

Following are the width measurements for the cap pattern.  If you plan on doing a rolled hem with a sewing machine,  the width needed is in parentheses.

Please choose one of the following pattern width measurements according to the size cap you are making:

Infants: 3 1/2"  (4")

Child's: 4 1/2"  (5")

Adults: 5 1/2" (6")

Measure horizontally from left to right edge (near top) the cap width measurement.  Place mark (red dot)

Measure down from top left corner the cap length pattern measurement and place mark (blue dot).  

Where the mark (blue dot) is, measure 2" (2 1/2") horizontally from left edge to right and place another mark (green dot).

Draw a straight horizontal line connecting edge of paper to green dot.  

Measure down from top corner and out to right 2" (2 1/2") for one of the following measurements:

Infants: 5"

Child's: 6"

Adults: 6"

Place mark (purple dot).

Draw a horizontal line connecting length measurement (green dot) to purple dot.

Measure down from red dot 2" and place mark (pink dot).

Draw a vertical line connecting red dot to pink dot.

Draw a curved line as shown connecting pink dot to purple dot.

Mark the top "fold".

Cut out pattern.

Lay paper pattern on top of fabric.  Match "fold" side of paper pattern to folded side of fabric. 

Pin

Cut out

At long sides of raw edges, finish with a serged rolled hem (if preferred)

Or sew a rolled hem by using a sewing machine. 

The next step is optional is you used a serged rolled hem.  It's to give the cap a more finished "boutique" look. 

On the curved long side of cap, fold under the rolled hem towards the wrong side and press. 

Stitch on top of the serger thread, wrong side up. 

Press flat.

Place cap under foot with right side of fabric facing up.

If cap has a rolled hem (done with a sewing machine) sew with elastic thread at left of stitching already sewn. Do not sew through three layers of fabric. (Sew on one layer of fabric only). 

If you're sewing on a cap that has a serged rolled hem, start sewing about 1/4 - 3/8" away from the straight (not curved) long side edge. 

Stop sewing row of elastic 1/2" from each end. 

When row is completed, lock stitch, leave needle in fabric, lift foot up and pivot. 

Move over about 1/4" to start a new row.  

Continue sewing in this manner for 3 or 4 rows depending on the look and feel you desire. 

Press ruffles flat.

Sewing back seam

Try cap on to check for fit.

Match up ends right sides together, pin.

Sew back ends together to form seam. 

Serge

Fold seam over flat.

Sew seam flat.