Recently I added the first two sets of printable embroidery stitch guides on my blog. These new cards can be used alongside the guides as a fun, easy way to teach new embroidery stitches to children.
Print the pdf at actual size on the thickest card your printer will take. Using a sharp, thick needle or drawing pin push through holes on all the dots marked on the cards. Put something soft (I use a thick sheet of felt) behind the card while you do this.
Depending on the age and sewing experience of the child you are teaching to sew you might need to thread their needle for them and knot the end. Then help them to sew the stitches onto the picture in the colour they want.