There is little difference between knitting a child's scarf and an adult scarf other than the size and colour. Because children come in different ages and sizes, you will need to measure your child for the proper scarf length. Consider that you may tie the scarf in the front when you decide how long you will make her scarf. Also consider the width of the scarf. Measure the length of his neck in the back. That should give you an approximation of how wide the scarf should be. With just basic knitting skills, a child's knit scarf should be easy to complete.
Purchase your supplies. You will need 1 skein of medium worsted weight yarn in the child's favourite colour. Children's knit scarves are quite often made from bright colours. There are also multicolour yarns that will give your finished child's scarf a striped effect. This gives an appealing appearance without the bother of having to change yarns while knitting. If you don't already have a pair of size 8 knitting needles, you will need to purchase them.
Cast on the number of stitches for the width desired for the child's scarf. Size 8 knitting needles will give you approximately four stitches per inch. Remember that the width will be slightly wider than it appears from the first row of cast on stitches.
Knit every row with the traditional "knit" stitch. When you have reached the length desired, bind off the stitches.
For a very young child, you may want to purchase a finer yarn and use smaller knitting needles. A fringe may be added to the ends of the scarf.