Rib on each end without flaring

softdough

The problem might be caused by loose cast on, or the ribbing itself is loose because of loose purl stitches or from the moving the yarn back and forth loosely from knitting and purling. Experiment with yarn scraps to find the problem.

If its the cast on, try a different method. Cable cast on usually is a good choice because its a knitted cast on and the tension will be closer to the rest of your knitting.

If its the rib stitch itself, one way to tighten it is to knit the knits through the back loop but keep purling normally. This is called the twisted rib stitch, and the first photo you posted looks like it used this stitch.

yerita

Muchas gracias por compartir

Sylvana

Very nice, go on and well done.

tital

Thank you very much for sharing.

Labrador6234

interessant

witte muis

Thank you very much for sharing.

Miyosi

Very nice. Thank you for sharing!

Kemeken

Paylaşım için teşekkürler :)

waitllf

thank you very much

toomuchreading

If you want to have the rib without the flair, your are going to have to do some test knits.  The way I do it on sweaters is to knit my rib, and then the first row of the stocking stitch, DECREASE (K2tog) evenly around after doing the rib.  It looks like you wont have to do too much decreasing to get an even side,  maybe 4-8 stitches, based on the picture.  The best thing that you can do is swatch, or just knit smaller samples, with various decreases.  Anyway, this is what I do frequently for my sweaters to get a straight side.  My rib will be winder and then for the stockinette Ill decrease evenly around.  Good luck with your testing.  The hats are so cute.