A knit bobble is a small bit of raised fabric that adds three dimensional texture to your knitting.
They are created by working a handful of stitches multiple times. This creates extra fabric in the spot being worked, which shapes the bobble, making it stand off your knit fabric.
Many knitters find working bobbles to be cumbersome because they involve turning your work many times. Backwards knitting makes working bobbles far less cumbersome.
3st bobble
K1-fbf in next st, turn and p3, SK2P. 1 st
using backwards knitting
K1-fbf in next st, Bk3, Sk2P. 1 st
4st bobble
Knit 4, turn and purl 4, turn and knit 4; pass second stitch over first stitch a total of 3 times; purl 3 and knit one through the back leg.
5st bobble
[(K1-fb) 2 times, k1-f] in next st, turn and p5, turn and k5, turn and p5, turn and k1, SK2P, k1, turn and p3tog. 1 st
using backwards knitting
[(K1-fb) 2 times, k1-f] in next st, Bk5, K5, Bk5, k1, SK2P, k1, Bk3tog. 1 st