Here is a very simple pattern to create a knitted napkin ring.
What you need
1 50g ball of patons double knitting
1 pair of no 8 needles
1 small button
Cast on 26 stitches
Knit 4 rows
5th row knit
6th row knit 2, purl until 2 stitches are left, knit these 2 stitches.
Work the 5th and 6th rows twice more.
Next row knit 2 *knit 2 together, put the yarn over the needle and knit next 2 stitches, repeat from the * until all the stitches have been worked.
Next row work in the same way as the 6th row,
repeat the 5th and 6th rows twice more.
Knit 4 rows and cast off.