Eyelash yarn is a novelty yarn. It has short lengths of thread all along the length of the yarn, making it look furry or fuzzy. Eyelash yarn comes in a wide variety of colours and has many textures -- metallic threads, ribbons and feathery threads. It can be fine, fuzzy, furry or chunky. Because the yarn is the main attraction, and it hides any pattern you might knit, the best stitch for eyelash yarn is a simple garter stitch, knitting every row.
Knit a swatch. Cast on 20 stitches and knit for 20 rows. Measure the width to see how many stitches per inch you are knitting. If your piece measures 4 inches wide, for instance, then you are knitting 5 stitches per inch. Use this figure to calculate the number of stitches you need to cast on for the width of scarf you want to make. If you want a scarf that is 8 inches wide, and you are knitting 5 stitches per inch, you need to cast on 40 stitches.
Begin your cast on by making a slip knot. Make a loop of yarn with your fingers about 20 inches from the end of the yarn. Put the tip of a knitting needle through the loop, wrap one end of the yarn around the needle to make a second little loop. Pull the loop through the first one, and tighten the two ends of the yarn so the remaining loop is snug.
Now, hold that needle in your left hand. Hold the other needle in your right hand. Put the tip of the right hand needle through the loop on the left needle. Wrap the yarn (not the tail) around the tip of the right needle and then work that tip through the first loop so that now you have two loops, one on each needle. Slide the new loop over on to the left needle, next to the first loop.
Now do it again -- slip the tip of the right needle through the new stitch on the left needle. Wrap the yarn around the tip of the right needle and pull it through the second loop. Now you have three loops. Push the new loop on to the left needle, so now there are three loops. Knit another loop and push it onto the left needle. Keep it up until you have the required number of stitches.
To knit the second row, you do the same thing with one change. Put the tip of the right needle through the first loop on the left needle. Wrap the yarn (not the tail) around the tip and pull it back through the first stitch. This time, slide the old stitch off the left needle and leave the new stitch on the right needle. Repeat until you have knitted a new row of stitches and they are all on the right needle. Then put the right needle in your left hand and do it all again. This is knitting, and the pattern it makes is called a "garter stitch."
Cast on the number of stitches you decided on and knit every row until the scarf is as long as you want or you run out of yarn. Because eyelash yarn has so many loose threads, make sure you are knitting with the base yarn, not the "eyelashes."
Bind off the last row. Knit two stitches. Pull the right hand stitch over the left hand stitch and drop if off the needle. Knit another stitch, pull the right hand stitch over the left hand stitch and drop it off the needle. Continue until you only have one stitch left. Cut your yarn with scissors and pull the tail tightly through the last stitch to make a knot. Weave the tail into the body of the scarf.
Needle size doesn't really matter. The larger your needles, the looser the weave will be when you are finished. If you are using larger needles, be careful to maintain tension on your stitches so they don't get sloppy. What is most important is to knit a swatch before you begin your scarf so you cast on the right number of stitches and obtain the size of scarf you really want.
Count your stitches often, as the eyelash yarn will hide what you are doing. If you find the number of stitches has changed from the number you started with, increase or decrease as needed to keep the scarf the same width. Wandering edges look sloppy.